FT 180 
,J5 
Jopy 1 

iViAi^niNE 
WOODWORKING 

Shop Notes and 
Note Book 

JENSEN 




MACHINE WOODWORKING 



Shop Notes, Note Books and Text, for Schools 
THAT use Machines in Connection with Woodworking. This in- 
cludes High Schools and Colleges as well as PkEvocATioNAL 
and Elementary Industrial Schools. 



BY 

Geo. Henry Jensen 
Director of the Prevocational School 

AND 

Industrial Arts Work in the High and Elementary Schools. 




Stockton, California 
Industrial Arts Department 
City Schools 
Stockton, California 



A 



Copyright, 1917 
by Geo. Henry Jensen 



©CI.A473411 
SEP 10 1917 



TO THE BOYS WHO ARE 

STRIVING FOR A MORE USEFUL FUTURE. 

TOWARDS SOCIETY 

AS WELL AS TO THEMSELVES, 



r7_- 



PREFACE 

Machine Wood-Working has been prepared for the purpose of 
furnishing specific and detailed information concerning the machines 
generally found in Manual Training and Industrial School Wood- 
Working Shops. A special effort has been made to compile this in- 
formation in connection with the standard trade practices and to point 
out practical safe-guards, "Insisted on by law in most states" and 
written in detail for California in chapter XVI. Too much emphasis 
cannot be placed on the necessity and use of safe-guards. The shop 
rules in chapter I should at all times be rigidly enforced as it will 
have the effect of reducing accidents to zero. 

The text also provides ample blank sheets to take the place of a 
note book which would otherwise be necessary in addition to the text. 

When using Machine Wood- Working as a text, the assignments 
should be sections or articles that relate to the work being done and 
not necessarily by page sequence. 

This material was prepared last year but cculd not be printed 
since other important demands were being made on the print-shop 
at the Prevocational School. It has been used by the author in ab- 
breviated form in his summer school classes for several years, par- 
ticularly at the University of California. Also in his own public 
school class teaching for years and has been found to be very help- 
ful and practical. 

The author takes this means of acknowledging the cuts and other 
material so generously contributed by the manufacturers as follows :- 

Oliver Machinery Co., Grand Rapids, 1, 2. 3, 39; American Wood- 
working Mach. Co., Rochester, N. Y., 13,35,36, 38, 46, 52; Henry Diss- 
ton & Sons, Philadelphia, 18, 19, 20, 21, 22, 24, 25, 27, 28, 29, 30, 31, 32, 
33, 34, 37, 40, 41, 42, 43, 44A; Grand Rapids School Equipment Co., 
Grand Rapids, 12, 14, 15; Russel Jennings Mf'gCo., Chester, Conn., 
49; Mummert Dixon Co., Hanover, Pa., 26, 53, 54; F. E. Wells & Sons 
Co., Greenfield, Mass., 50; The Fox Machine Co., Grand Rapids, 58, 



CONTENTS AND LIST OF ILLUSTRATIONS 

Gumming Attachment for Grinder, p. 22; Fig-. 29, Comparison of 
Correct and Incorrect Gumming, p. 23; Fig. 27, Soft wood, p. 24; 
Fig. 28, For Hard Wood, p. 24; Fig. 29, Right and Wrong Gumming, 
p. 25; Fig. 30, Upper Cut Tooth, p. 25; Fig. 31, Filing back on the 
Periphery Line p. 25; Fig. 32, Comparison of Old and 
Gullet Style Tooth, p. 26; Fig. 33, Sections of Single Cut Files; 
Sections of Double Cut Files, p. 27; Fig. 34, Flat Bastard, Mill, Half 
Round, Round, Square, BluntBend, Taper, andSlim Taper Files, p. 28. 
CHAPTER V -.---. 30. 

31, General; 32, Use; 33, Operation and Adjustment; 34, Speed 

and power; 35, Points Always to be Remembered, illustrations: 
Fig. 35, Single Surfacer with Individual Motor Drive and Enclosed 
Switch and Rheostat, p. 29. 
CHAPTER VI ------- 36,* 

36, General; 37, Use; 38, Operation; 39, Speed and Power; 40, How 
to Care for Band Saws; 41, Why They Break; 42, Brazing; 43, Set- 
ting and Filing; 44, Large Band Saws. 

i llustrations ; Fig. 36, Band Saws "A" Guide Post "E" 
Ripping Fence, p. 36: Fig. 37, Mohawk Dutchman Saw 
Guide, p. 37; Fig. 38, Tension and Tilting, p. 38; Fig. 39, Band Saw 
Properly Guarded and With Re-sawing Attachment, p. 39; Fig. 40. 
Band Brazing Tongs in Position after Heating, p. 40; Fig. 41, 
Wheels and Clamp For Hand Filing. (Larger scale view of clamp 
and brazing tongs at top.), p. 40. Fig. 42; Narrow Band Saw Setting- 
Machine, p. 42; Fig. 43, Automatic Filing Machine, p. 43; Fig. 44, 
Band Saw Filing and Setting Machine p. 44; Fig. 44a, Band Saw 
Mill, p. 46. 

CHAPTER VII- MORTISING MACHINES - - - 48. 

45, General; 46 Operation; 47 Speed and Power; 
ILLUSTRATIONS: Fig. 45, Vertical Hollow Chisel Mortising Machine, 
p. 48; Fig. 46, Automatic Vertical Mortiser, D. C. Motor Connection, 
enclosed switch and rheostat, p. 49; Fig. 47, Hollow Chisel With 
Bit, p. 50; Fig. 48, Hollow Chisel Without Bit p. 50; Fig. 49, Fxten- 

V 



CONTENTS AND LIST OF ILLUSTRATIONS 

CHAPTER XIV EXHAUST systems - - - - 70 

^2, Exhaust Systems; 73, Speed and Power. 

CHAPTER XV POWER transmission - . . 71. 

74, General; 75, General Care; 76, Splicing (Wire Whang, Belt Hook 
and Glue); 77, Belting Rules; 78 Drive and Speeds, (a) Drive, (b) 
The Driven, (c) Speed, (d) Rules for Speed of Pulleys, (d) Rules for 
surface speed, (e) Fbrmula for speed of pulleys, (f) Exercises. 
ILLUSTRATIONS : Fig. 68, Single and Double Ply Splices, p. 73; Fig. 
69, Belt Clamp and Rods, p. 74; Fig. 70, 71, Simple Method of Lac- 
ing, p. 74; Fig. 72 Pulley side. p. 75; Fig. 73, Outside of Belt, p. 75; 
Fig. 74 Lacing Specifications, p. 76; Fig. 75, Straight Stitch Lace 
for Odd Number of Holes, p. 76; Fig. 76,' Flesh Side for Odd Num- 
ber of Holes, p. 77; Fig. 77, Grain Side for Odd Number of Holes, 
p 77; Fig 78, Beginning Lace for Even number of Holes, p. 77; Fig. 
79, Hinge Lace Looks Same on Both Sides of the Belt, p. 77; 
Fig. 80, Hinge joint Avoids Stiff Lace, p. 78; Fig. 81, Hole Punched 
and Beginning of Lace for Hinge Lace, p. 78; Fig 82, Arc of Contact, 
p. 81; Fig. 83, Belting Specification Sketch, p. 81; Fig. 84, Belt 
Length, p. 82, Fig. 85, Common Drives, p. 82; Fig. 86, Speed Indi- 
cator, p. 83; 

CHAPTER XV] SAFETY orders - - - - 84. 

79. Safety Provisions; 80, Circular Rip Saw; 81, Crosscut Saws; 
82, Band Saws; 83, Wood Jointers; 84, Sanding Machines; 85, Mor- 
tising Machines; 86, Shapers; 87, Tenoning Machines; 88, Lighting; 
89, Gears, etc.; 90, Multiple Unit Drive; 91, Recommendation; 92, 
Gears; 93, Belts; 94, Pulleys; 95, Clutches; 96, Belt Shifters; 97, 
Shafting; 98, Set Screws; 99, Sprockets; 100, Flywheels; 101, Grind- 
ing Wheels; 102, Ladders; 103, Stairways. 

Note; Blank sheets in front as well as back to be used for notes. 

-The Author. 



y 



CHAPTER I 

INTRODUCTION 

1. Introduction- Before endeavoring to learn how to use the 

machines the student should come to a realization of the danger in- 
volved in the use of any machines in the wood-shop, through care- 
less or indifferent operation. Machines even when properly safe- 
guarded are always dangerous to the careless operator, "Safety First" 
becomes a reality in the shops where these machines are used. It is 
necessary at all times to concentrate on the particular work which 
you are doing and not to pay any attention to what is going on at 
other machines, or in other parts of the room. 

The machines in these chapters are described in the order used 
when milling material for any job. so far as possible. However, by 
looking over the contents it will be seen at once that it may be nec- 
essary to grind the jointer knife or file a saw before these have been 
studied. The order of the machines is similar to that of the squar- 
ing up process when working at the bench using hand tools. 

Never hurry if you would avoid accidents. 

The following shop rules should be observed at all times: 

1. All machines in this shop are properly equipped with safety 
devices. Belts and motors are housed and enclosed so as to elimi- 
nate all danger of burning the operator. 

2. However, the machines are dangerous when used by a careless 
operator, or, when operated in a careless manner. 

3. No student should ask permission to use any of the machines 
until he has been properly taught by the instructor how to use 
same first, in class demonstration, then by individual questioning 
and demonstration. 

4. Each time a student wishes to use any machine, he must first 
get permission from his instructor to do so, even though it is necessary 
for him to use a machine or machines, m.ore than once during a 
period. 



CHAPTER II 



SWING CUT-OFF SAW 

2.- General The swing cut-off saw, Fig. 1, is supported from 
the wall and ceiling and has a large counterweight to pull it back to 
the wall after making a cut. The 
frame is of heavy cored construction 
and rests against the wall back of the 
table when not in use. The table has 
rollers, the face of which are slightly 
higher than the table. This is done 
in order to make it easier to move the 
stock while working at the saw. The 
motor rests in the top of the frame 
and drives the saw by means of an end- 
less belt. In the best types of saw the 
construction is such that the belt can 
be tightened without cutting it. Fig- 
ures 1 and 2 show the slotted holes 
just above the arbor which permits of 
this adjustment. Another advantage 
of this construction is that the saw 
arbor may be removed from the frame 
for rebabbeting the bearings. 

This machine, while not as dangerous as some of the other 
machines in the mill room, must be properly guarded in order to 
insure maximum safety to the careful operator. 

The swing frame should have a knuckle guard, one type of which 
is illustrated in Fig. 2. In this case the wire belt forms the knuckle 
guard. The saw itself should also be guarded, and an excellent 
type of guard for this purpose is shown in Fig. 2. A study of the 
figure will reveal to you that as the saw leaves the wood, the guard 
is lowered, dropping back and covering the saw when not in use. 




FIG. I. 



SWING CUT-OFF 
SAW. 



J 



MACHINE WOODWORKING 



3. Use- This machine is used when milHng stock. Its purpose 
is to cut stock to length and should not be used for squaring the 
ends of pieces to finished lengths, although some manufacturers 
state that their swing saws will cut accurately enough for this. 
You will readily see that a swing cut-off saw is a necessity in every 
modern mill room because the long pieces of stock cannot be cut to 
length advantageously on the saw table. 

4. Operation- Note that the back of the table is graduated so 
as to cut any particular length without marking. Place the board 
in position so that the proper length 
can be cut. (A stop may be clamped 
to the back of the table if a num- 
ber of pieces of the same length 
are to be cut.) Grasp the han- 
dle firmly and do not pull the saw into 
the wood too rapidly. The motion of 
the saw is down and into the wood 
and for this reason if you do not have 
a firm hold, or have started too swift- 
ly, the saw will stick and the belt will 
slide. Should this happen, keep a firm 
handhold and push the saw back until 
it begins to revolve again. 

5. Speed and Power-- A three horse 
power motor will afford sufficient pow- 
er for ordinary work. In large mills 
where very heavy stock is cut a larger 
motor is necessary. When using the 
14" saw it should run at the rate of 

3000 RPM. 

FIG. 2- SWING CUT-OFF 

WITH BELT AND KNUCKLE GLIAKD, 
ADJUSTABLE SAW GUARD, AND AD 
JUSTMENT FOR TIGHTENING BELT. 




CHAPTER III 

JOINTER OR BUZZ PLANER 

6. GENERAL- The jointer. Fig. 3, also called buzz planer, may 

be used for quite a wide range of work if properly manipulated. 

Its original purpose was to plane a working face or to take wind out 




FIG. 3--J0INTER WITH FLAP GUARD. 

of a surface and to plane an edge at right angles to that face. It 
is also used for planing glue joints and dadoing. Fig. 6, shows a 
jointer with parts labeled. 
7. THE HEAD- Formely all jointers were equipped with square 

heads, illustrated in Fig. 4, 
but these are so much more 
dangerous to the operator be- 
cause of the fact that in case 
of accident one is apt to have 
an entire hand or at least most 
of the fingers of the hand 
drawn into the machine. This 
can be verified by comparing 
the larger opening, Fig. 4 
with thatof thecircularhead. 
Fig. 5. While it is still dan- 
gerous to the operator to get 
his fingers in the machine, 




FIG. 4. -SQUARE HEAD. 



MACHINE WOODWORKING 5 

8. Tables— The tables, Figure 6, are mounted in such a way that 
they can be drawn from the cutter head on a level, independently 
of the device for raising and lowering them. The best tables are pro- 
vided with steel lips located close to the cylinder head. When the 
lips are of the same material as the other parts of the table they are 
not as serviceable. The front 
table, or the one at which the 
operator stands when he, 
begins to run a piece of wood 
over the jointer, is the one 
that determines the size of the 
cut to be made on a piece of 
stock. The most desirable type 
is the one that has a hand 
wheel, Figure 6, on the back 
side of the table and permits 
the operator to stand in front of 
the machine while adjusting . FIG. 5-SAFETY HEAD 

the depth of the cut. With the old type it is necessary to get down 
and reach below the machine to make this adjustment. 

The back table should not be adjusted except with the assist- 
ance or permission of your instructor. It is easily gotten out of ad- 
justment if tampered with by a novice. This may cause an accident, 
resulting in disfugured knives and an injured operator. 

9. Operation.-- Assume the position in Figure 6 and be careful 
at all times that you do not slip, which may result in a bad acci- 
dent to hands or fingers. A piece of rubber matting nailed to 
the 'floor is a great aid to easier and safer operation. Cleats are 
sometimes nailed to the floor when matting is not available, but 
are an inconvenience when sweeping. 

10. Working Face - To plane a working face assume the position 
shown in Fig. 6. The piece to be planed is placed on the front table 
after being certain that the gauge is set for the proper thickness 
and pushed slowly over the revolving cylinder, being careful at all 




6 



MACHINE WOODWORKING 




■iTARTIfiQ- 
3 WITCH 



shoved 
referr- 
readily 



times to keep the stock firmly 
on the table. This may be ac- 
FRD//rComplished with both hands 
on the surface of the board 
being planed. A precaution 
must always be taken, espec- 
ially with beginning students by 
using the wooden mitten shown 
in the top of Fig. 7. This is 
placed in the back end of the 
piece which is being 
over the jointer. Again 
ing to Fig. 6, it will 
be seen how easily it is to drop 
the right hand down upon the 
revolving cylinder thus caus- 
ing a very serious accident, 
which can be avoided by the 
use of the mitten and push 

stick, which is also shown in Fig. 7. Be sure at all times to use 

the safety guard. There is only one exception to this which will be 

noted later. Always run the stock so that the knife will cut with 

the grain. 
11. Jointing An Edge- Planing a 

working edge on the jointer is similar 

to squaring up a working edge at the' 

bench. The piece is set against the 

fence and fed very slowly in a man- 
ner similar to that shown in making 

a working face Fig. 6. If the stock 

is wide so that the top edge comes 

above the fence and fed very slov.'ly 

it will not be necessai >' to use the 

mitten or push stick. It is best always to feed the stock so that it w ill 



FIG. 6- WORKING FACE 







I IG. 7- US1^G A PU 

i( K I OK Narrow ,- 



'A>CK. 




FIG 8-CUTTING A CHAMFER 



MACHINE WOODWORKING. 7 

cut with the grain, however, fairly good work can be done joining 
against the grain if fed very slowly. 

12. Chamfering- The 

jointer may be used for 
chamfering as illustrated 
in Fig. 8, by tilting the fence 
so as to cut the desired angle. 
Remember that the rule 
learned in hand planing, to 
plane the end grain first still 
holds good. 

13. Rabbeting- When us- 
ing the machine for rabbet- 
ing it is necessary to remove the jointer guard. This 
should be put back as soon as the operator has completed the rabbet- 
ing, because a guard should be attached at all times for regular joint- 

' ' ^ ing. As a rule, machines 

are equipped with rabbet- 
ing arms (brackets). I^ is 
not possible to do efficient 
rabbeting withouf'them. 
14. Sharpening— For grind- 
ing of jointer knives refer to 
the chapter on grinding. 
After grinding, it is neces- 
sarv to set the knives very 
FIG 9-JOINTING AN EDGE carefully. To get them quite 

true, place a try square on the back table so that the end of the 

blade projects out over the knife test in this manner for the 

entire length of both blades, and tighten very securely. Then 
joint, by using the device shown in Fig. 11. 

15. Speed And Power— The jointer should be run at the rate of 4500 R. 
P.M. The small 4 inch bench jointer is usually equipped with a 1-4 
H. P. motor and the cvlinder should be run at the rate of 5200 R. P. M 





FIG 10- RABBETING 



8 MACHINE WOODWORKING 

8 inch 2 H.P. and cylinder 5000 
R.P.M. ; 12 inch 3 H.P. and cyl- 
inder 4800 R. P. M . ;16 inch 3 to 
5 H-P. and cylinder 4400 R.P. 
M. ; and 20 inch 3 to 5 H. P. and 
cylinder 4000 R.P.M. The cyl- 
inder is usually equipped with 
a 4 inch pulley. 

16. Points Always to be Ob- 
served While Operating the 
Jointer. 

1. Be sure that the back table is properly adjusted and locked, 
and that the fence (gruide) is fastened so as to give the angle you 
are attempting to cut. 

2. Use a guard at 
all times, except 
when dadoing. Good 
types are shown in 
Figs. 5 and 6. 

3. Use a wooden 
mitten or specially 
provised stick (Fig. 
8) of some kind in 
pushing flat and 
narrow pieces over 
the revolving cylind 
er. 

4 Be sure to inspect 
the depth of the cut 
FIG. Ii-JOINTING DEVICE and see that the 

fence is locked before beginning to push stock over it. Do not change 
the fence when cylinder is in motion. 

5. For good work, push the stock over the jointer slowly. It is 



THUMB SCREW 




i 



MACHINE WOODWORKING. 9 

best to have the knives cut with the grain. 

6. For straight cutting and in making joint edges be sure that the 
stock follows the rear table. (This means to keep it flat on the 
rear table from the time it leaves the jointer head. 

7. To straighten a curved piece of stock, begin on the crowned 
edge or side. Begin on one side of crown and stick to it until you 
have a straight edge. 

8. If the rear table is too high it leaves a crowned edge, if too low, 
a hollow edge. 

9. Do not use a jointer for planing to thickness. After the work 
ing face has been cut, the stock should be taken to the planer. 



CHAPTER IV 

SAW TABLE 

(Circular Saws - How to Fit and Use them.) 
17. General— The saw tables or circular saws as they are also called 
are used in two types as a general rule. One of these is known as 




FIG. 12-DOUBLE ARBOR SAW WITH GUARD and SPLITTERS 



the Double Arbor or Universal Saw Table, Fig. 13. (it also has a hori- 
zontal mortising attachment in this case). 
These machines are the most dangerous of all of the machines 



MACHINE WOODWORKING 



11 



usually found in school woodworking shops. They are probably not 
as dangerous as the Tenoner and the shaper, but these two machines 
are usually omitted in the school equipment, except in the highly 
specialized trade schools, because of the danger to the operator. 

Before learning more about the circular saw you must come to a 
realization of the extreme necessity for the implicit observance of 
all instructions concerning the use and operation of these machines 
whether single or double arbor type. 

The Universal saw, Fig. 12, has a hand wheel "A" for revolving the 
two saw arbors making it possible to change very quickly from rip 
to cross cut saw or vice versa, and for raising or lowering the saw 
which determines the distances it projects above the saw table while in 
use. Remember that the saw should never project farther above the 
table than is absolutely necessary for the thickness of stock being cut. 

The guard "C" and splitter 
"D" also shown in Fig. 12 
are necessary as "Safety De- 
vices." The guard should be 
used at all times when poss- 
ible. The splitter is a farther 
safeguard because it keeps 
the stock from pinching after 
it has passed the saw. 

Another hand-wheel " B" 
is provided which makes it 
possible to tilt the table from 
its position to an angle of 45^. 
(Use the lilting index to get 
the desired angle). Always 
see that the clamp is set before 
using the saw. This holds true whether the table is tilted or level. 
The fence "E" in Fig. 14 may be tilted so as to cut a chamfer just 
RS in th^ case of the jointer. iThe fence must never be m.oved 




FIG. 



33-SINGLE ARBOR SAW WITH 
GUARD AND MORTISER. 



MACHINE WOODWORKING 



13 



while the saw is in operation. The left side of the table is on rollers 
so that it can be run l)ackwafcland forward, while sawing, by releas- 
ing a stop under the table. 

The Single Arbor saw is like the Double Arbor in most respects, 
except that having only one arbor it is necessary to remove the nut 

on the arbor and 
change the blades 
when changirg 
from lip sawing 
to cioss cutting 
work. This nut 
is turned counter 
clock wise to 
tighten. Miter 
blades may be had 
which answer 
fairly well for both 

rip and cross cut- 
ting work but to 
do both success- 
fully it is necess- 
ary to keep it well 
fitted at all times. 
18. Operation- 
Preparatory to 
ripping stock 

which is the simplest operation on the circular saw (l)make sure 
that you have the rip saw and that it projects through the table 
only as far as necessary for the stock which you are going to rip. 
(2) Make sure that the fence is adjusted for the proper width. 
Use the scale on the top of the table which is shown in Fig. 11 for 
adjusting the fence. When you have it approximately adjusted 
tighten the clamp and tlien make the adjustment exact by means of 




FIG. 14-TABLE AND GAUGE GRADUATIONS 



14 MACHINE WOODWORKING 

the micrometer adjustment. Notice the locating- holes in the top of 
the table for adjusting the fence to cut very wide stock. (3) See that 
the clamp on the tilting hand wheel, "B"in Tig. 12 is set, and if you 
are using the Double Arbor Saw be sure that the clamp under the 
table is set so that the top will not roll. (4) Last but not least see 
that the guard and splitter are in place. You are now ready to 
shove the stock over the saw. When the end of the board starts 
over the saw make sure that the edge is ag:ainst the fence and you 
will have no difficulty in ripping parallel with the edge and getting 
the exact width of stock for which the fence has been set. As you 
' push the board over the saw. stand either to the right or to the left 
of it. Should the board twist in any way and become caught in the 
saw you could not stop it or get out of the way in time to prevent a 
serious accident. When ^"he stock is narrow, or it becomes neces- 
sary for your hands to come near the saw use a push stick as shown 
in Fig. 7, while operating tlie jointer. 

When cutting stock to length the miter cut-otf gauge "A"in Fig. 14 
is used. This gauge has a groove into which a stop rod is fixed and 
on the end of which is a stop, as shown on the miter gauge in this 
figure. Not only is it possible to cut stock to length and at ihe same 
square the ends, but by using the adjustments indicated it is pos- 
sible to cut for iriangles, miters, hexagons, octagons, etc. In using 
the miter gauge place the stock against the stop and gauge, after 
you have adjusted the rolling side of the table so that it will move 
with the stock while cutting to length. It will readily .be seen that 
a miter gauge cannot be used in this manner with the single arboi' 
saw table which does not have the sliding top. To do similar Vv'ork 
on a plain saw table the ur.ivei'sal miter gauges shown at "B'' in 
Fig. 14 are used. They slide in grooves in the table top and may 
be used on either side of the saw. Strips of steel are provided for 
filling these grooves when the universal miter gauges are not being 
used. This is necessary since the grooves would otherwise fill with 
sawdust and hinder the operator in pushing the stock over the table. 
In using the ripping fence as a stop for cutting stock to 



MACHINE WOODWORKING 15 

leng-th be sure to attach the metal clearance block to the fence which 
is provided for this purpose. Some machines do not have them, in 
which event a block of wood should be used and held in position by 
means of a wooden clamp. 

19. Cutting Tenons- The saw table may also be used for cutting- 
tenons when making mortise and tenon joints. The cut-off guide or 
the universal gauge is used for this and set as for a square cut. If the 
universal saw is used, the rolling section should be released. Attach 
the clearance block to the ripping fence. If attaching to a plain 
saw table which does not have a clearance block a block of wood 
may be clamped in place, using a wood or iron clamp. Then set the 
fence so as to cut a tenon of the proper length (remember that saw 
kerf must be justified when reading graduation). Raise the cross- 
cut saw so that the saw will project just enough above the table to 
cut the depth of the shoulder required for the tenon. Then clamp 
the shaft so that the saw will not drop. Before begining to saw 
make sure that your rails have been cut to proper lengths. The saw^ 
may be reset for cutting the shoulders on the edge of the stock if nec- 
essary. The best practice is not to cut shoulders on both ends as 
just explained but to remove the fence and use the stop rod on the 
cut-off guide. For the end of the tenon which has had shoulders 
cut against the stop on the stop-rod and then the tenon at the other 
end, will insure having exactly the same length between shoulders. 
After the shoulders have been cut the rip saw is used to cut the cheeks. 
Raise the saw so that it will just cut into the kerfs made by the 
cross-cut saw. Set the fence so that when the cheeks have been 
ripped from each side that the tenon will be of the thickness already 
determined by the saw kerf made while cutting the shoulders. 
You may cut both cheeks of the tenon a' the same time by using 
two saws with steel washers between them to allow thickness of the 
tenon. Remember that in cutting a 1-2" tenon you will have to sep- 
arate the saws more than half an inch or about one-sixteenth more 
than the thickness you desire to saw, due to the set in the saws. 



16 



MACHINE WOODWORKING 



20. Speed And Power.~Saws from 10" to 16" are in general use on 
saw tables. The 12" size is probably used more than any other. Motors 
from 5 to 7 1-2 horse power are used, depending on the size of the 
saw and the thickness of the stock to be cut. A 12" saw should be 
run at the rate of 2850 R. P. M., while the 16" saw being larger 
would only require a speed of about 2200 R. P. M. As a general 
rule it may be stated that the circular saw should be run at a speed 
which will give it a surface or cutting speed of about 9,500' per 
minute. If run too slowly, power is wasted, the saw does poor work, 
gets out of order more quickly, etc. On the other hand, if run at 
too high a speed, and particularly if the saw is dull, it will cause it 
to heat and buckle. 

A good method for installation of individual motor drive is shown 
in Fig. 15. If 
a single arboi* 
saw- is used it 
will be neces- 
sary to provide 
a belt tightener 
or use a sliding 
base on the mo- 
toi*. A careful 
study of the 
solid and dotted 
lines will show 
you the guard. 
21. Dado Heads 

Dado Heads are the tools used in connection with the saw-table for 
the purpose of cutting grooves "withthegrainof the wood" and dadoes 
"across the grain of the wood". Fig 16 shows the head completely 
assembled as it appears when placed on the saw-mandrel. To under- 
stand just how it is put in place you are referred to Fig. 17, where 
one outside cutter has been placed on the Mandrel and several of the 
center cutters, (also called fillers), have been put in place. 




FIG. 15~M0T0R DRIVE GUARDED 




FIC. 



16-DADO HEAD READY 
FOR OPERATION 



MACHINE WOODWORKING 17 

The dado heads come in different sets and may be made to cut 

grooves from 1-8" to 4" in width. However, if used in school shops 

it rarely happens that a width wider than one inch is needed. A 

set No. 4 will cut g-^-ooves 1-8" to 1" 

width by sixteenths. The outside 

cutters are both 1-8" in thickness 

and may be used singly or as a pair 

to cut the 1-4" groove. To adjust 

for the different width grooves 

place the outside cutter (also called 

groover) on the arbor and then 

add the inside cutters of the nec- 
essary thickness to give you the 

proper width to cut after the other 

outside cutter has been placed on 

the mandrel. 
-Just as much care should be exercised in using the dado heads as 

is exercised while using the circular 
saw. While it is a safe tool for the 
careful worker who follows instruc- 
tions, it is dangerous for the care- 
less operator. 

22. Points Always to be Observed 
While Operating the Saw Table. 

1. Do not cross-cut without using 
the miter cut-off gauge or the 
universal miter gauge. 

2. Always use a clearance block on the fence when using it as a 

stop while cross-cutting. 

:i Have the saw only as far above the table as necessary for 

stock which is to be cut. 

4. Always have stops on the fence or table when making 

which do not go through the stock and are shorter than the 

length of the stock. 




'IG. 



17 ILLUSTRATINC; PARTS 
of DADO HEAD 



the 

cuts 
full 



18 MACHINE WOODWORKING 

5. Do not adjust the fence while the saw is in motion. 

6. When ripping stock, be sure that the edge is held firmly against 
the fence as it first starts over the saw, and keep it there. 

7. Do not stand back of the piece as it passes over the saw (if thrown 
back it will injure you seriously) but keep to the right or the left of it. 

8. Make sure the hand wheel and fence are clamped before starting 
the saw. 

9. If the saw binds while ripping, lift the end of the piece so that 
it comes clear of the saw. [This will be easy if the saw is not set 
too high.] 

10. Use a push stick when ripping narrow or short stock. 

11. Do not pick up pieces from the table when the saw is in motion, 
use a stick to push or rake it off. 

12. Do not use a dull saw, it is both costly and dangerous. 

13. Make sure that the guard and splitter are in place before start- 
ing the saw. 

14. Stop the saw when you leave to do an errand in another part of 
tht^ shop, or, while you use another machine. 

15. Always drop the saw below the table top when leaving the saw. 
23. Fitting Circular Saws —No matter how the saw is made nor how 
good the steel from which it is forged, it will noc work in a satis- 
factory manner unless it is at all times properly set and sharpened. Not 
only will a saw in poor condition do poor work, but is very dangerous 
to the operator. As a general rule, the distinction between a poor me- 
chanic and a good mechanic can be discovered at once by the condition 
in which he keeps his tools. The poor mechanic uses dull tools, while 
a good mechanic always has his tools in first class condition. 



FK;. 18-BRIAR DRESS CIRCULAR FIG. 19 SWAGE TYPE CIRCULAR 

SAW. SAW. 

Rip saws are fitted in two way."^. Cno. spring set briar dress, as il- 
lustrated in Fi:^. 18, the other, swage type, as illustrated in Fig. 19. 
As a rule, all shops use boih types of saw. The swage set saw 



MACHINE WOODWORKING 19 

requires more power since it has a greater capacity (one tooth 
practically doing the work of two of the spring set type) . As already 
stated, either of these types will do good and satisfactory work when 
properly fitted. 

24. Fitting the Rip Saw With Swage Set- The first step in fitting the 
saw is to joint it. By jointing we mean to get the saw perfectly 
round so that the teeth are all of an even length. This should be 
done with the trade mark up on the saw. Proceed by placing a 
piece of grinding stone, emery wheel, or an oil stone that is no 
longer used for sharpening purposes, against the saw while the saw 
is revolved at a moderate speed (saw should project slightly above 
the table while jointing). This method of jointing of course is not 
necessary when a sharpening machine is used. 

After the saw has been jointed, the teeth are all filed to a keen 
point, being careful to file just to the marks left by the stone in joint- 
ing so that all of the teeth will be of the same length, and the same 
shape, otherwise they will not swage properly. 

Until you have had a great deal of experience, it will be necessary 
to use a gauge in filing the teeth to shape after jointing as illustrated 
in Fig. 20, in order to get all of them of the same shape. The gauges 
are to be had for the askingfrom certain manufacterers of saws, and are 
included with the saw 
swage when it is pur- 
chased. Use a 10" mill 
file with round edge 
so as to keep the gullets 
round (see art. 29 for?^ 
files). 

After the saw has 
been properly filed it 
is swaged so as to give 
the teeth clearance 

when they enter the FIG. 20 GAUGE FOR REGULATING THE 
wood. If they do not SHAPE OF TEETH. 






20 MACHINE WOODWORKING 

have proper clearance they dull very quickly and also heat, which 
causes the saw to lose its temper. Some type of saw swage, one of 
'which is shown in Fig. 21, is used for this swaging or upsetting. 

S 

''-^ G \ 

iiliijLHmiiw: ! 1 



When examining 

the swage it will 

be seen that onej 

side is convexj 

and that the 

other side is FIG. 21- SAW SWAGE 

straight. The convex side is used for upsetting the teeth "H" in 

Fig 21, and then it is straightened with the other side "G" also 

shown in Fig. 21. 

Be sure that the swage is held in such a manner that the angle of 
the teeth is net changed. Also, it should be held so as to drive from 
the front under side. This is necessary in order to give it the proper 
"rake". If a saw is always given the necessary rake in swaging, 
the diameter is not reduced as rapidly. If, on the other hand, the 
swage brings pressure to bear from the top side, it causes it to de- 
crease in diameter much m.ore rapidly. Hold the swage at the same 
angle for all of the teeth, so as to avoid getting it out of round. 

After swaging, the saw is again jointed as it was in the beginning 
then filed so that all of the teeth are brought to a sharp point. Be 
sure that you file at right angles to the side of the saw. If you 
fail to do this, the saw will not run properly. If it is filed at an 
angle it will lead in and out of the stock according to the direction 
of the angle. This, of course, will make it impossible to do good 
parallel ripping, and will soon put the saw out of commission. 

Next, dress the sides of the teeth the same as when you are filing 
hand saws. This may be done by placing the saw on the arbor and 
holding a stone with a right angle end on the table and against the 
side, while revolving it slowly by hand. There are tools for this, 
called side files that may be used instead of this improvised devise if 
they are available. A goo d type is illustrated in Fig. 22. The file 
is adjusted for the proper width by means of the set screws B. Af- 



MACHINE WOODWORKING 



21 



ter locking these, the tool is held by means of the clips at "A". The 
points of the three set screws must at all times be kept against 
the blade. 

25. To Fit The Rip Saw With Briar Dress. -To 
fit a briar-dress (Fig. 18) rip saw, you proceed the 
same as in the case of the swaged tooth saw, with 
the exception that the points of the teeth are bent 
alternately instead of being swaged, as stated in 
the operation just described. 

To set the teeth, use a set as illustrated in Fig. 23. 
The anvil is set so that its edge will strike the tooth 
Sj^about 1-4" from the point. By means of the screw 
^^gauge the desired angle of set is obtained. Use a 
FIG. 22-SlDE No. 3 saw set for circular and cross cut 
FILE saws from 14 to 20 gauge. To get the best re- 

sults, as little set as is absolutely necessary is 
given. This causes less waste since it decreases the amount of saw- 
dust made while sawing. 

Some prefer an adjustable setting stake for this work. A good 
type is shown in Fig. 24. It may be adjusted to set saws from six 






FIG. 23- HAND SAW SETFOR CIR- 
CULAR AND CROSS-CUT SAW 



FIG .24- AD.JUSTABLE SETTING 
STAKE FOR CIRCULAR AND 
CROSS-CUT SAWS. 



to thirty inches in diameter, by moving the cone"A"in or out to fit 
the saw. Certain portions of the face side of the hardened steel 
anvil "B" are beveled more than others so that by adjusting it and 
raising or lowering the cone "A" any desired set can be obtained. 
26. Gumming--In order to understand what is meant by a properly 



22 MACHINE WOODWORKING 

gummed saw, refer to Fig. 25. The circular gullet below point "C" 
shows a gullet which has been properly fitted. If the gullet is filed 
square as at "A" and"B", especially if the teeth are dull, the saw 

c 




FIG. 25- CORRECT GUMMING AND THE RESULT OF SQUARE GULLETS 
dust accummulating in the square gullet will cause the saw to crack 
as at'D". 

Experienced saw fitters tell us that the round file is the proper 
tool forgummingasaw. 
However, in modern 
practice the emery 
gummer, Fig. 26, has 
taken the place of the 
hand-file. This attach- 
mentmay be purchased 
with certain grinders, 
or may readily be made 
in any blacksmith shop 
for a grinder that does 
not have this attach- 
ment. A free cutting 
wheel should be used, 
and little pressure ap- 
plied at all times. This 
is done to avoid heating GUMMING 




FIG. 26- 
ATT.\CHMENT 



FOR GRINDER 



MACHINE WOODWORKING 



23 



of the teeth. If they become blued or case hardened by the emery 
wheel they are liable to break. 

In gumming, go around the saw a number of times, insteadof attempt- 
ing to finish each tooth at one operation. Not only is a more uniform 
gullet obtained in this manner, but you are much less liable to over- 
heat the teeth. The emery wheel (or composition stone) should be 
jointed frequently so as to remove the glaze and retain the proper 
face. Before gumming on the emery wheel, study "Saw Gumming" 
in the chapter on grinders. 

27. Fitting Cut-off Saws- Cut-oif saws are set in the same man- 
ner as the briar-dress rip saw. In fact, they are fitted in the same 
manner, except that the teeth are given more bevel both front and 
back. The proper shape of the tooth for soft woods is shown in Fig. 
27, the proper shape for hard wood in Fig. 28. When gullets are 
cut as illustrated in Figs. 27 and 28 they require frequent gumming. 

Fig. 29 shows one tooth 
filed with gullets that have 
been properly gummed. A 
saw filed in this manner is 
liable to breakage the same 
as indicated at "D" in Fig. 
25. The type of tooth 
shown in Fig. 30 and desig- 
nated as under cut, does not 
require as frequent gum 





29 



COMPARISON OF CORRECT AND 
INCORRECT GUMMING. 



ming as the old type of cut-off ^^^ 

saw. The cut-off saw, as in 

the case of the rip saw, requires frequent filing. 

28. ECONOMY IN SAWS -A good, deep, full cut instead of a 
light, scraping one means a saving of of both time and files when 
sharpening saws. The depth of cut taken at each revolution of the 
saw determines the distance on the face of the tooth which is dulled, 
for example, each tooth cutting 1-30", requires 30 teeth to cut 1" 



24 MACHINE WOODWORKING 

while if each tooth cuts 1-15" , only 15 teeth will be required to cut 
thel". In other words the fiber of the grain of the lumber must 
be broken 30 times in one case, but only 15 in the other. The tooth 
breaking the fiber 1-15" will do it with nearly as much ease and with 
about the same power as when breaking 1-30". This example illus- 




Fig. 27- FOR SOFT WOOD 






Fig. 28- FOR HARD WOOD 



trates that one tooth becomes dull 1-15" under the point while the 
other becomes dull for 1-30", but it must be noted that it requires 
practically the same amount of saw-plate, file and time in either case 



MACHINE WOODWORKING 



25 



Fig. 2t>-RIGHT 
AND WRONG 
GUMMING 




Fig. SO- 
UNDER CUT TOOTH 
(Does not require 
frequent gumming) 



(strike a happy medium and do not go to extremes). On the tooth 
"\ _.. in Fig. 31, A A are the original lines of the 

tooth, dotted line B shows where the point 
'^ first wears; dotted line CCC shows how it 
j^~- should be filed back on the periphery line; but, 
too frequently, on account of the long surface 
to be filed, operators file the top only as repre- 
sented by the dotted line D. It is readily 
seen that by filing back on the dotted line CCC 
the saw has been reduced in diameter only from 
Fig. 31-FlLlNGBACKON dotted line E to F, while filing from the top 
THE PERIPHERY LINE of the tooth the reduction will be shown by 
dotted line from E to D. 




26 MACHINE WOODWORKING 

Thus we see that by fihng on top five times as much of the saw 
has been wasted as by proper filing. This difficulty is overcome by 
the use of the gullet tooth as shown in Fig. 30 and 
Fig. 32 which outlines both the straight tooth and '\^__^^^ 
the gullet tooth. Using the gullet tooth leav o ~^^^ 

excuse for filing on top. To hold the saw while \ 

filing use an tidjustable circular saw-fiHng vise, or I N^ 

make a wooden one in the shop. / ) 

29. False Economy-- It is false economy to endeav- -.^.- ^ 

or to save time by not filing often. One authority Fig. 32- COMPARI- 
says: *"Many hours' time have been wasted and SON OF OLD AND 
many saws ruined through the false economy of ^^ULLET STYLE 
not sharpening often enough. We have never 
seen a saw mill where it is not true economy to sharpen saws from 
two to four times in a full day's sawing. A saw properly swaged ur 
set, will stand from two to five filings before it needs re-swaging or 
re-setting." 

For average work (part hard and part soft woods) it is a safe rule 
to file once for every three hours of sawing. 

30. Files— No tool is used for as many different purposes and has as 
many different kinds and styles as the file. Not only are there sev- 
eral hundred different kinds of regular files but several thousands of 
regular and special files combined, all of which are designated by 
name according to the length, shape and grade of cut. Those in or- 
dinary use are flat, mill, hand, square, round, half-round, taper, 
and slim-taper. Most files are now made by machine although jour- 
neymen still exist who cut even the finest files by hand. 

By noticing the fineness and the narrowness of the teeth of the 
dead-smooth file it will be realized how much skill is required in cut- 
ting these fine teeth, often barely visible to the naked eye. Fig. 33 
illustrates the different cuts of files in common use. These illus- 
trations are engraved from files 12" long, consequently if the 
the file which you use is longer than 12" , the cuts will be coarser, 

* Disston, Handbook on Saws. 



MACHINE WOODWORKING 



27 



if shorter they will be finer in proportion. 

The single-cut files, which are shown in the illustrations have 
but one course of chisels cut across the surface, which are parallel 
to each other or oblique across the file blank. The double-cut file has, 
as shown in Fig. 33, two courses of chisels cut across each other, The 
first coarse is called the over-cut and the second course is called the 

Sections of Single Cut Files 






Second Cut 
Sections of Double Cut Files 



Smooth 






Bastard 



Second tut 

FIG. 33 



Smooth 



'--up-cut. This results in leaving fine points as compared with the 
chisels on the single-cut file. The terms l)a-itard-cut, second-cut and 
smooth-cut, as printed in Fig. 33 mean coarser or finer cut files, or, 
having more or less teeth to the inch. A rough-cut file is coarser than 
those shown in the illustration and the dead-smooth is a finer file. 

Files are made in various sizes and shapes as already stated. 
Those in more common use have already been named and are illus- 



28 



MACHINE WOODWORKING 




Flat Bastard 




Mill 




«ma3!3S5:raE:::;:v.^»x ^. 



Round 



Square 



Blunt Band 



Taper 



Slim Taper 



trated in Fig. 34. The flat tiles taper from near the center to the 
point, are narrower and slimmer at the point, are double-cut on the 
sides and single cut on the edges. These are used for coarse and rough 
work. 



MACHINE WOODWORKING 29 

Mill files are forg-ed similar to the flat files. Some have one and 
others two round edges. They are used for filing saws, knives and 
and other high grade work; having chisel teeth they leave a smooth- 
er surface than does the one with double-cut teeth. 

The round files are single-cut and are usually forged tapering 
though some are of uniform size from heel to point. 

Taper files are made of three cornered steel and usually taper, 
being smaller than the other three-square files (not shown in the fig- 
ure) are single-cut and have teeth on edge as well as on sides, but 
not cut quite to the point. They are made bluni and are used for 
filing band saws and all small saws. Some tapers are made longer 
than others from the same size steel and are called slim taper. The 
advantage of this file is that it gives a greater length of stroke in fil- 
ing. 

Some tapers are forged tapering at both ends instead of having 
a tang at one end for handle, thus making two files in one. 



CHAPTER V 

THE PLANER OR SINGLE SURFACER 

The single surfacer, also called planer, shown in Fig. 35 is 



of a 




FIG 35-SINGLE SURFACER WITH INDIVIDUAL MOTOR DRIVE 
AND ENCLOSED SWITCH AND RHEOSTAT. 

double belted type. By this is meant that power is transmitted to the 
cylinder, or cutter head, on each end instead of driving it from only 
one end as in the case of the jointer which is single belted. (Some 
cheap makes of single surfacer are single belted. ) The cylinder is 
similiar to that of the jointer except that the square cylinder is still 
being used to a considerable extent. l:[owever, the better class mills 
and shops are beginning to use the cylindrical type entirely. Upon 
the sides of the planer it will be seen that the belts and gears which 
drive the feed rolls, are entirely separated from the cylinder drive. 
The hand lever, just above the hand wheel on the left of the machine, 



MACHINE WOODWORKING 31 

as you stand on the side from which the stock is fed, controls the feed. 
The fast revolving cylinder cannot be stopped suddenly even if the 
power is cut off, but by loosening the lever the feed roll may be 
stopped at once. This is a safety in case of accident, and when 
too heavy a cut is being taken, loosening the lever enables the motor to 
pull through without blowing a fuse. After cylinder gains speed again 
the lever is tightened so as to again start the rolls, though it will us- 
ually be necessary to lighten the cut. The smoothness of the cut de- 
pends on tlie speed to which the feed rollers are adjusted. In the cheap- 
er makes of machines only one speed is possible. As a rule this is a- 
bout 24' per minute, but on better grades of machines it is possible 
to adjust for a speed 16' to 32' per minute. Special high speed ma- 
chines run soft woods as fast as 75' per minute. Planers vary in width 
from twenty to forty inches and special machines have greater width 
than this. The machines usually found in school shops have 
a capacity for planing stock up to 6" or 7" in thickness and 24" wide 
but some machines have a capacity for planing stock considerably 
thicker. If the machine is a good one and is properly adjusted, it 
will plane stock as thin as 1-16" . Some surfacers plane both sides at 
one operation and are known as double surfacers, while still other 
machines surface four sides at one operation. If the rheostat is not 
near the machine, the electrical installation should include a single 
wire with switch for throwing out the rheostat without leaving the 
planer. It may be opened and closed in one operation; this throws 
out the rheostat, but leaves it ready for starting. 

32. Use-After jointing the fac9side of a board, the surfaser is the 
machine which planes the stock to the thickness. As explained in the 
introductory chapter, the machines are described in the order of use 
as far as possible. The ordinary procedure is (1) to cut to length on 
the swing saw as explained in Chapter II, (2) to make working face 
and edge on jointer Chapter III, (3) rip to width on saw table. Chap- 
ter IV, and (4) plane to thickness on planer as described here when it 
will be ready to square to length and then model. 

This machine will not plane material out of wind, as is sometimes 



32 OIL YOUR MACHINES 

thought by beginners. To do good work the face side should be plan- 
ed on the jointer before cutting it to thickness. However, when sur- 
facing stock for ordinary work, or material that does not have any 
wind in it, both sides may be planed on the surf acer. 

33. Operation and Adjustment-The hand wheel, just below the 
gauge on the left side of the machine in Fig. 35 is used to raise and 
lower the table so as to adjust it for the wood which is to be planed. 
Find the thickest part of the piece which is to be planed and set it 
so as to take a cut of about one-sixteenth of an inch in thickness. It 
is sometimes necessary to raise the back end of the board slightly 
higher than the top of the table in order that the corrugated feed 
roll may grab it and draw it into the machine. Feed so that the 
cylinder will cut with the grain. It next passes under the chip-breaker 
pressure bar which is adjusted either by a spring or weight (weight 
in this case. ) After passing the pressure bar it now meets the 
cylinder head and the chips follow the curve of the breaker and fly 
out over the machine. Just after the board passes under the cylinder 
head it encounters the back pressure bar which holds it firmly to the 
bottom feed rollers so that the stock is cut to a uniform thickness. 
After the back pressure bar the stock of course passes between the 
two feed rollers to the back of the machine and continues on through. 
When planing a number of pieces always run the thickest ones 
through first taking off about a sixteenth of an inch at a time. 

It is a good plan to have brushes under the bottom feed roller in 
order to keep the shavings and other matter from sticking to them 
which results in marring the stock. Ordinary scrub brushes may be 
used and can be secured in some improvised manner so that the 
bristles remain firmly against the rollers. 

Considerable care and practice is necessary in adjusting the sur- 
facer. The feed rollers do not require adjustment if they have been 
properly adjusted at the factory, except as they have become worn. 
The bottom feed roller must project only as far above the table as is 
absolutely necessary to carry the stock. Adjust the corrugated roller 
so that it has just pressure enough to move the stock. The corrugated 



OIL YOUR MACHINES 33 

roller and the smooth feed roller on the back of the machine are both 
adjusted with special reference to knives. The top roller in the 
back should have as little pressure as necessary to move the stock. 

Adjustment of the planer knives is the most difficult part and 
may be done by placing parallel blocks on the table under the cylin- 
der. It requires considerable experience to do this with accuracy and 
dispatch. The best class of modern planers have the grinding attach- 
ments on them which makes it unnecessary to remove the knives 
except as they wear out. Several manufactures have portable grind- 
ing devices which make it possible to grind and adjust both planer 
and jointer knives without removing them from the heads. This, of 
course, effects a great saving of time. See index for cut and des- 
cription of portable grinding device. 

When feeding the stock through the planer do not get behind the 
moving stock since it happens that the stock is thrown back and 
would result in injury to the operator. Keep to either side of it. 

Never plane short pieces. When feeding several pieces through 
at the same time be sure that you put them in straight and allow 
sufficient space between so that they will not interfere with each 
other while passing between the feed rollers. 

34. Speed and Power-The cylinder speed of a single surfacer should 
be from 4200 to 5000 R. P. M. From 4 to 7J H. P. motors is required 
to operate this machine depending on the size and the kind of stock 
to be cut. Generally speaking if the machine is not over 24" in 
width a 5 H. P. motor is ample. 
35. Points always to be Remembered 

1. Remember what has been said about the feed — that it can be 
stopped instantly by loosening the feed lever. 

2. Do not leave the machine running when you are through using it, 
or while going on an errand before you continue. 

3. Do not plane pieces less than one foot in lengUi. 

4. Never plane two pieces that are against each other — leave a 
space between them if two pieces are being put through at one time. 



34 OIL YOUR MACHINES 

5. See that this machine, as well as any other that you use, is prop- 
erly oiled at all tinnes. 

6. In starting the motor, be sure that the planer is at its maximum 
speed before you throw over from the starting point. 

7. If there is a shaving exhaust, be sure that the hood is in place and 
the fan is started as you begin work. 

8. To set for thickness, drop the table lower than required and raise 
it back to the desired thickness. Also, see that the feed weights are 
properly set before beginning to feed the machine. 

9. Feed so that the knives will cut with the grain. 

10. Do not feed the material into the planer in such a way that the 
ends of the boards will strike or catch in the guides at the edges of 
the bed. 

11. Have the lumber ready before starting your machine and be 
sure you know the thickness to which you are going to plane. 

12. As much as possible should be planed at one setting of the plan- 
er. This not only saves time but insures even thickness. l:[ere is 
seen the reason for planing the poorest side of the board first. 

13. Do not do all of the cutting at one place on the knives when nar- 
row work is being planed. Distribute it equally throughout the 
length of the knives so that they will wear down and dull evenly. 

14. In running through very long boards, a roller horse the height of 
the table should be placed at the proper distances back from the plan- 
er. If such a horse is not availible and you have only a few such 
boards to plane, hold the back end up. 

15. For very accurate work, test a trial piece by measuring with a 

ruler. 

16. In planing wide pieces that are to be ripped later, always rip them 
before planing if the boards are warped. 

17. Warped lumber cannot be straightened on the planer. It is use- 
less to attempt it. Take it to the jointer. 

18. In planing lumber s2s that has not had a face jointed on it, most 
of the stock should be removed from the poorest side. Do this first 
since you do not know how far down the poor place on the stock ex- 



OIL YOUR MACHINES 35 

tends, being carefu), however, to leave enough to take one cut on the 
other side so as to leave it smooth. 

19. Do not walk on lumber after it has been piled. 

20. Boards should not be dropped heavily on the floor. 

21. Exercise judgment in the depth of the cut to be taken. Re- 
member it is easier on the machine to go through once taking 1 16" 
cuts than it is to force it through taking 1 8" cuts. 

22. Remember that if the planer begins to slacken speed or to check, 
the feed may be stopped by means of the hand lever and so left un- 
til the cylinder gets up speed again. 

22. Comparison of the I 'laner and the Jointer- (a) The planer 
smooths, but does not make a true face on warped stock as the joint- 
er does. (b) The jointer cuts away equal to the amount at which 
it is set while the planer leaves stock equal to the amount at which 
it is set. (c) The jointer will smooth the second face but does 
not leave it parallel with the first. The planer does. 



CHAPTER VI 

BAND saws: how TO OPERATE, SHARPEN, ETC. 



36. General -- Band 
saws are made in right 
and left hand types, 
the right hand being 
more universal. Figs. 
36 and 39 show right 
hand machines which 
are properly guarded. 
Instead of the wire 
door as the top some 
machines have a wood- 
en frame of panel con- 
struction. The bottom 
guard in this case con- 
sists of two cast iron 
doors. Sometimes the 
lower guard is made of 
panel doors, or, wire 
frames similar to the 
guard on the top of the 
wheel. The guide post, 
shown at "A"' in Fig. 
36 is a very essential 
part of the machine. 
The Mohawk Dutch- 
man saw guide which 




FIG. 36 



BAND SAWS "A" GUIDE POST "E" 
RIPPING FENCE 

is attached to this guide post is shown on a larger scale in Fig. 37. 
The guides on either sides of the blades should be set quite close to 
the saw. The wheel, "B", on which the back of the saw runs. 



SAFETY FIRST 37 

should be set so that the teeth just clear the two gruides. 

The top wheel of the band saw is adjustable and can be raised or 
lowered by means of the handwheel at "C" in Fig. 88, to accomodate 
the different 
sizesof saws. 

The small 
adjusting 
wheel at 
"D " is 
for tilt- 
ing the 
wheel so 
that the 
saw will 

not run off 
when you 
start the ma- 
chine. 

When us- 
i n g thin 
stock , it in- 
volves con - 
s i d e r a b 1 e 
waste to 
plane down 

inch boards FIG.37- MOHAWK DUTCHMAN SAW GUIDE, 

to, say, I" to I" in thickness. By means of a re-sawing attachment, 
it is possible to split the boards without much loss of material. A 
good type of re-sawing attachment which can be i)ut on the band 
saw is sh(»wn in Fig. 39. This saw feeds at the rate of about 12^ pei- 
minute. Most band saws also have a tilting table with micrometer 
adjustment and accurate graduation. 

37. Use--Up to the present time the machines described have been 




38 



SAFETY FIRST 



necessary to square up stock to a certain definite dimension. In mak- 

ng projects where the construction is very simple, or when the stock 

is ready to assemble after squaring, no modeling is required. 

The band saw is one of the machines which is used in modeling, that 

"~""^ ^— --- - jg^ cutting to certain patterns such as 

rockers for chairs, and other form 
work. The Sander, mortising machine, 
boring machine, etc., are for modeling 
and finishing. 

There are times when the band saw 
is used in ripping to width. For work 
of this kind, a fence such as is shown 
at "E" in Fig. 36 is necessary. Rip- 
ping to width on a band saw is not ac- 
curate, however, like ripping on the 
saw table. 

38. Operation-- The guide "A" in 
Fig, 36 should be kept as low as poss- 
ible at all times, when operating the 
handsaw. When sawing, keep in front 
of the saw and do not step around in 
line with the direction of travel of the 
saw wheel. Should the saw break, 
there is no danger if the machme is 
properly guarded, and you remain at 
the operator's station. 

Always use as heavy a blade as is possible for the work at hand. 
If, when making sharp turns, the saw is not able to make the curve 
which you desire, or you keep backing up the blade, it is either too 
wide or it doesn't have enough set. It is considered by experts to be 
a better practice to cut out rather than back out if you find that you 
cannot make th? curve which you are attempting, by means of the 
cut already started. There are cases however, when it is neces- 
sary to back out in order to keep from spoiling a piece of work. When 




FIG 38. 



-TENSION AND 
TILTING 



SAFETY FIRST 



39 



this happens it is best to stop the machine and get the instructor 
inform you as to the best method of freeing the piece of stocky 
Just before you throw in the power, if the machine which you use 
is an ndividual motor drive, it is well to start the saw by whirling 
he wheel, this helps the motor gain headway without undue strain 
(the otL; machines we have studied do not require this). If on a 




FIG 39 BAND SAW PROPERLY GUARDED AND WITH 
RE-SAWING ATTACHMENT 
line shaft, shift the belt slowly and let the saw get a start before 

you give it the full width of the belt „ „ P motor This 

S9 Soeed and Power- Ordinary work require a 3 H P motor, inis 
nowefXl be transmitted to the drive shaft either by means o 
bek or chain since the direct drive machines do not seem to prove as 

universally satisfactory. 4-^ii^w«- for SO" saw 

The speed of the drive wheel should be as follows, for 30 saw 

650 R. P. M.. 32" saw 600 R. P. M., 34" saw 550 R.P.M., and 



SAFETY FIRST 



40 

36" saw 500 R. P. M. 

40. How To Care For Band Saws-Good jud-ment must be ex- 
ercised m Dreaking in a new band saw if it is to give long and effi 
cient service. A new saw will not do as much work as one that ha« 
been perfectly adjusted and adapted to the wheels. A new band 
saw seems to be unusually elastic, and until it has been used for a 
short time, it does not seem to get its proper bearings 

It should not run more than a half-houi- without stopping, for the 




FIG. 40-ERAZING TONGS IN POSITION AFTER HEATING 



Fitr 




WHEELS AND CLAMP FOR HAND FILING. (larger 

. SCALE VIEW OF CLAMP AND BRAZING TONGS AT TOP.) 



SAFETY FIRST 41 

first few times that it is used, and above all, be sure to release the 
tension when the saw is no longer m use. This is particularly essen- 
tial while breaking- in a new saw, but should be observed at all times, 
if the maximum efficiency and endurance is desired. 

41. Why They Break-- Breakage is caused in several ways, but 
only the more conspicuous ones will be mentioned. If a saw is used 
with too heavy a tension, it is bound to break. Sometimes in "heavy 
duty" work the tension is made stronger after the saw becomes 
warm and expands. Then, if this tension is not reduced after the 
saw is stopped, it is bound to break when the saw cools and contracts. 

Saws used when dull, rot only do unsatisfactory work but soon 
crystallize and break with the least unusual strain. It is very poor 
policy and a dangerous procedure to use saws when dull. 

The operator should remain in his position in front of the saw, so 
that if the saw does break, he will not be in a position to suffer acci- 
dent. Do not use the machine unless it is properly guarded. 

Another reason for breaking saws is guides not properly set or 
constructed. The guide shown in Fig. 37, the Mohawk Dutchman 
Typf, eliminates to a great extent,- the possibility of cracking and 
crystallization, and consequently lengthens the life of the saw. The 
wheel forming the back guide has a concave surface on its periphery. 
In addition to this, the wheel is set at an angle so that the back of the 
saw passes diagonally across the point of periphery of the wheel 
which causes it to revolve. With the point of bearing constantly 
changing, it prevents the saw grooving the surface of the wheel. 

Both wooden and steel guides are provided for the sides of the 
saw. The saw will give much better service if these wooden guides 
are used at all times. In the same way, the guide just below the 
table on the saw, should have wooden guides not only on the side of 
the blades, but back of the saw as well. If these have not been 
provided they can readily be made and attached in the shop. 

42 Brazing -- A brazing clamp with tongs is illustrated in Figs. 
40 and 41. Before joining, the ends must be filed at an angle so as 
to give a good bevel fit to the ends, (Be sure that the joint after 



42 



SAFETY FIRST 



brazing will be no thicker than any other part of the saw.) Both 
ends of the saw are then secured in the clamp, as shown in Fig. 40. 
The edges must be parallel, that is, the back edges of the two ends 
of the saw must form a straight line, otherwise the saw will run 
badly and break soon after it has again been placed on the ma- 
chine. This may be kept straight, if the back edge of the saw is 
placed firmly against the straight edge which forms the back part 

of the clamp. 

For a flux, use a thin 
coating of borax paste. 
This is prepared by grind- 
ing the borax on a speci- 
ally prepared slate, with 
a small amount of water. 
A thin piece of sheet sil- 
ver solder, just the size of 
the joint, is then placed 
in the lap. The brazing 
tongs heated to a bright 
red, are next placed over 
the joint, as shown in 
Fig. 40. However, be 
Fig. 42. NARROW BAND SAW sure that you first 

SETTING MACHINE scrape the scale off 

between the jaws of the tongs. An old file or similar tool may be 
used for this. 

The joint is then held with hot tongs until the solder has through- 
ly melted. If a second pair is at hand it is well to follow this up with 
another pair of tongs that have been heated to a dull red. This helps 
to set the solder and prevents it from chilling too rapidly. A carriage 
clamp or similar iron clamp may be screwed on the jaws to hold 
them in place while taking care of the second pair of tongs, if it is to 
be used. If the joint is too thick after brazing, dress it to the thick- 
ness of the saw. 




SAFETY FIRST 



43 



--^ 



43. Setting and Filing— When small band saws are set by hand 
the process is very much like that of setting and filing an ordinary 
cross-cut hand saw. But to do this conveniently, it is necessary to 
have two large wheels (either wood or metal) and a vise, Fig. 41, on 
which to hold the band saw while fitting. The more common meth- 
od however , is to use a machine for setting and an automatic ma- 
chine for filing. A narrow band saw setting machine is illustrated 
in Fig. 42. This machine 
sets all of the teeth uni- 
formly and may be adjust- 
ed to set saws g" to 1|" in 
width with the teeth spaced 
l-16"to i" . The vise auto- 
matically grips the blade 
while the teeth are being 
set and prevents in this way 
the twisting of narrow saws. 

This machine should run 
100 revolutions per minute 
which enables the operator 
to get a new saw in about 
5 minutes. The automatic filing machine is shown in Fig. 43. 

This machine is intended for a power drive or may be arranged to 
drive by hand. It will take saws of the same specifications as the 
setting machine in Fig. 42. 

Old saws with uneven teeth may be filed to exactly the same 
height and made as good as new. This gives more satisfactory re- 
sults than when the saws are filed by hand. This machine uses 6 " 
taper saw files, and should be run at the rate of 50 to 60 revolutions 
per minutes. 

Fig. 44 shows a combined filng and setting machine and is op- 
erated as follows: 

Placing the Saw in the Machine 
*"1. Remove the file before placing the saw in the machine. To do 
*FroiTi Instruction Sheet of Wardwell Mfg. Co. 




V i 

FIG.43 AUTOMATIC FILING MACHINE 



44 , SAFETY FIRST 

this, turn thumb screw E and draw the file out throug'h the socket 
holder. 

2. Loosen the butterfly nut H which allows the vise jaw to open, 
also see that I is loosened enough to allow the saw to pass in be- 
tween the setting points. Now place the saw in the vise and tighten 
H and I sufficient to allow the saw to be pulled through by hand, 
but not so loose as to chatter when being filed. 




Fig 44 BAND SAV^ FILING AND SETTING MACHINE 

3. The back edge of the saw should rest on the supports D and C by 
which it can be raised or lowered in the vise. 

Have the entire tootii shiow slightly above the top of the vise under the fil- 
but only partly above in the vise where the tooth is set. 

4. Loosen the two pair of setter screws J and K so that the setter 
point will not be in action while adjusting the file. 



SAFETY FIRST 45 

Adjusting the File and the Pawl 

5. Replace the file and before tightening E, turn the drive wheel of 
the machine partly around by hand so as to allow the file to come 
down aud rest between the teeth, by so doing you can see at what 
angle the file should be tightened in the holder. Then tighten E- 

F and G allow the file to be raised or lowered a trifle whenever necessary. 
G should always hold the tang of the file a fraction higher than the point of the 
file is held by F. By a little attention to this point, the teeth can be filed obso- 
lutely free from any burr. E when loose allows the file to be turned to present a 
new face and F and G are used as adjustments for files of various thickness. 

A Seven Inch Slim Tapered File is Preferable 

When using a 4',-. in. extra slim taper file for fine teeth, change the cam roll- 
er screw to the inner hole in the cam. Keep the file that comes in the machine as 
a sample to buy other files. We recommend any good quality of file. The sup- 
port holding the tang of the file, as well as the bushing in the end of the sash arm, 
are both reversible to accommodate difi'erent size of tangs or points. 

6. Thumb screw A regulates the length of the stroke of the pawl or feed 
finger; adjust this screw so as to allow the pawl to come back just 
one tooth and push that tooth ahead under the file. 

This is easily accomplished by moving by hand the drive wheel back and forth, 
but not at any time completely around, by so doing one can observe that both the 
file and pawl are working correctly. 

7. Thumb screw B is to regulate the pawl so that it will not come 
in contact with the file. Should the file touch the pawl or feed finger, 
turn B until it clears. This screw also regulates the amount of cut 
required to be made on the face of the tooth. 

Adjusting the Setting Attachmeni 

8. By loosening screw M the setting attachment can be slid along 
sleeve L so as to bring the setter points in direct line with the saw 
tooth. This sho'jld be done when the file is resting in the tooth and the 
pawl is traveling back. When in aline, tighten M. Loosen the two 
wing nuts J and adjust the two thumb screws K which regulate the 
amount of set desired, then tighten the wing nuts J, and in so doing 
see that the setter points or dies travel close along the top of the vise. 



46 



SAFETY FIRST 






CO 

> 

D 

> 




SAFETY FIRST 47 

Now turn the drive wheel around slowly one complete revolution. See that the set- 
ter points set the teeth on the same side that they were previously set, this will a- 
void breaking the teeth. Operate the machine by hand for a dozen or more revolu- 
tions, watching the setter point set the teeth. If your saw is an old one with ir- 
regular teeth, run it through the machine a couple of times so as to even up the 
teeth before attempting to set them. 

Keep the machine well oiled. Operate not over 65 revolutions per 
minute, glower is better for the file. Occasionally pull out and 
clean the vise of any fine dust that may have worked into it. If the 
driving cam and slides are kept well oiled the machine will last for 
many years." 

44. Large Band Saws-The band saw is used in preference to the 
circular saw in large mills. The circular machine is used in the 
small portable outfits. A right hand band saw mill is shown in Fig. 
44 A. 



CHAPTER VII. 



MORTISING MACHINES 

45. General— In general mortising machines are divided into two 
groups — vertical and horizontal and are a monument to the progress 
since the time wher^ mortises were made by burning with a red hot 

iron. The vertical type Figs. 45 
& 46 is the more logical since the 
stock is placed on a table and the 
bit enters the wood instead of 
having the wood forced onto the 
bit as is the case with most types 
of horizontal mortisers such as 
are in general use in schools in 
connection with the saw iable is 
shown in Fig. 12. 

The hollow chisel bits, Figs. 47 
& 48, are used in this machine. 
When first placed on the market 
it was referred to as the machine 
"that bores a square hole" and 
has been named the hollow chisel 
mortising machine. The square 
chisel just referred to Figs. 47 
and 48, has a special foim of bit 
to bore all inside of it and runs 
at a high rate of speed. The bit 
runs slightly ahead of the chisel 
which forms the square hole, for 
in )-eality the chisel is obliged to 
cut the corners and the chips are carried away by the bit. The dif- 
ferent machines have different adjustniants for the table and since 
no ore explanation would be sufficient for all machines, this, for the 




FIG. 45 
CHISEL 



VERTICAL 
MORTISING 



HOLLOW 
MACHINE 



(BELTS PROPERLY GUAROED. ) 



KEEP YOUR TOOLS SHARP 



49 



most part is left to your instructor. 

46. Operation-- In setting? up the for mortising, exercise care in 
selecting the proper bushings. Make sure that the set screw passes 
through the bushing and that it rests on the flat side of the bit, and 
above all, make sure that the bit is slightly ahead of the chisel. 

Then push the foot 
pedal to the floor and 
hold it there while ad- 
justing the table so as 
to cut a mortise of the 
proper depth. Adjust 
the stops and fence and 
you are ready for oper- 
ation. 

Some machines are 
equipped with a clamp 
or compound table. 
This differs, from the 
plain table in that the 
table moves back and 
forth. The table may 
be tilted to the right 
and to the left. The 
angle to which it may 
be tilted is from 30" to 
45°. 

Hollow chisel bits 
are made in various 
sizes such as J", |", 

111 511 311 in 




Fig. 46:- Automatic Vertical Mortiser; 
Motor D. C. Connection, enclosed switch 
and rheostat. 



1", etc. 
more cuts 
will make 



But taking 
the i" bit 
amortise larger thanf". 
For examples" mortise 



50 



KEEP YOUR TOOLS SHARP 



F1G.47 HOLLOW CHISEL 
WITH BIT. 




LENGTH BLADE - 




SHOULDER 



OPENING 



CUTTING BEVELS 



FIG. 48. HOLLOW CHISEL WITHOUT BIT. 



can be cut with this 
same bit and will re- 
quire four cuts in- 
stead of one as would 
be the case if using 
the 5" bit. In a sim- 
ilar way the §" bit 
readily makes a mor- 
tise I" X I2'', etc. 




Fig. 49- EXTENSION LIP COUNTER-SINK BIT 

(This saves 50 percent of time, power, and operator time in counter-sink bor- 
ing. The mortising machines are often used for boring, and particularly the hor- 
izontal type. In this connection a universal chuck and twist drill bits may also 
be used to advantage. ) 

47. Speed and Power-- A 2 to 3 H P. motor is required. The count- 
er shaft should be run at a speed of 900 rpm. which will give the bit 
a speed of 3500 to 4000 rpm. Fig. 46 shows a D.C. motor connect- 
ion with fcmclosed switch and rheostat. When ordering machines 
which are to have a motor base, it is necessary that the manufactur- 
er be informed in regard to the make of motor which is to be used. 



CHAPTER VIII. 



WOOD TURNING LATHE. 

48. General- There are several different forms of wood turning lathes 
in use. Some have an overhead drive and tun from a counter shaft. 
Others have a motor head where the lathe in Fig. 50 has a cone pulley. 
The other type, and the one most used is the one shown in Fig. 50, and 
is called an under-drive. These lathes are also built in different sizes. 
The size is determined by the largest diameter of the stock which it 
will turn, and the longest length which can be turned between centers. 

The stock 
is secured 
in the live 
center 
which is 
held in the 
head stock 
spindle. 
This is also 
called the 
spur cen- 
ter. 

The tail 
spindle 
which is 
adjustable 
contains the dead or cup center which keeps the stock in place. 

49. Use-- The wood turning lathe is used to turn pieces to cylindrical 
form. In addition to this, all kinds of variations developed ficm 
regular coves and beads are possible. Space does not permit a 
detailed description of the care and operation of this machine. How- 
ever, it may be stated that the best results are obtained when printed 




Fig. 50-UNDER-DRIVE TYPE OF WOOD-TURNING LATHE. 



52 TAKE TIME TO BE CAREFUL 

instructions, supplemented by demonstrations on the part of the in- 
structor are used. 

50. Speed and Power-- | H. P. is necessary when an individual 
motor drive is used on the average medium size lathe as found in 
school shops. As already stated in article 48, the under-drive type 
is more economical. While a | H. P. motor is necessary for an in- 
dividual drive in order to meet maximum conditions, a 3 H, P. is 
quite ample to drive a line of six or eight lathes with individual con- 
trol. It is readily seen that in a group of six or eight lathes only a 
few will be doing heavy duty work, since most of the work attempt- 
ed in school shops is of a small diameter. The drive shaft referred 
to may be noted in Fig. 50, and is inside of the casing marked "en- 
closed shaft." The drive shaft and pulley should be of such a di- 
ameter as to give a spindle speed of from 700 to 3000 R. P. M. In 
the case of the machine represented in Fig. 50, the speed of the 
drive shaft should be approximately 600 R. P. M. 



CHAPTER IX. 

SANDERS. 

51. General-- Sanders are used to smooth the surface after planing 
so as to prepare it for stain, varnish, or any other kind of finish. 
The difi'erent sanders are belt, disk, spindle, dium, or a combination 
of these. 

52. Belt Sander- A typical style of belt sander is shown in Fig. 51. 




Fig. 51-BELT SANDER 
The pulleys at either end supporting the sand 
distance apart, determined, of course, by the 
is used. The idler pulley at the top makes it 
belt down on the work, which has been placed 
of the hand block shown on the table in the H 
Some sanders have an idler at either end. 
vertically, and moves from front to back in oi 
surface of pieces placed on the table. 

Canvas sand belts are used for this purpose, 
happens that paper sand belts are substituted 
factory as the canvas belts. These belts are 
glued together in proper lengths. A piece of 



belt may be placed any 
length of table which 
possible to push the 
on the table, by mf ans 
gure just refen ed to. 
The table is adjusted 
•der to sand the entiie 

although it sometimes 
but are not as satis- 
bougt in rolls, and are 
canvas may be placed 



PRESENCE OF MIND AIDS SAFETY 



54 



on the cloth side and ghied and clamped similar to the manner in 
which a leather belt is g-lued. Another method is to remove the 
sand from five or six inches of canvas, and use this as a lap in gluing. 

53. Disk and 
Spindle Sand- 
ers— The disk 
and spindle 
Sander illus- 
trated in Fig. 52 
is one of the 
safest types in 
use. The disk, 
made of glued 
upstrips, is 
covered with a 
piece of heavy 
Brussels, and 
acts as a pad 
for the sand 
paper. The 
iron band 
around it holds 
the paper in 
Fig. 52— DISC AND SPINDLE SANDER place. 

The vertical spindle is for shaping curved work, and usually has 
two or three different sized spindles in order to make possible a va- 
riety of work. 

It has an oscillating vertical movement which makes it possible to 
use the entire surface of the sand paper, and does smoother work. 

54. Speed and Power-- Belt sanders, as described in Fig. 52, are run 
at a surface speed of about 2200 feet per minute, and require a 2 H. P. 
motor. The disk and spindle sander, described in article 53, should 
have a speed of 700 r. p. m. for disk, and 1200 r. p. m. for the spindle. 
A 2 H. P. motor is required for power. 




PRESENCE OF MIND AIDS SAFETY 55 

The large drum sanders used in furniture factories having- three 
to four drums 12" in diameter should run at the rate of 800 r.p.m., 
and require from 5 to 15 H.P. 



CHAPTER X. 



TOOU MOLOEft 



GRINDERS AND GRINDING 

55. General-Until within the last few years, most of the grinding 
in wood working shops was done on grindstones, where a sandstone 
wheel was used as the cutting agent. This was a much slower pro- 
cess then the present oilstone 
grinder. It is still insisted by 
some that the grindstone gives 
better results. However, it is a 
fact that all progressive shops 
and factories are adopting the 
oil stone grinders for sharpening 
edge tools. The grinder in Fig. 
53 is one of the several efficient 
types of this kind of machine now 
on the market. 

56. Drive and Speed.-- The ma- 
chine may be driven from a line 
shaft as provided for in Fig. 53, 
but is usually equipped with an in- 
dividual motor, one ho^^se power 
being all that is required for this 
machine. The upper arbor 
should run at a speed of 1650 r. 
p.m., the oilstone wheels at -230 
r.p. m. 

57. Oilstone Wheels and Oil- The wheels used are made of a special 
composition that is adapted to the grinding of edge tools when run 
in oil. The composition is so proportioned as to give the greatest pos- 
sible abrasive qualities along with slow wearing features. The 
stone abf^orbs the oil which penetrates to the interior when the 




Fig. 53- COMBI.MATIONGi\IXDP:R. 




CARELESSNESS INFLICTS ITS OWN PUNISHMENT 57 

wheels are not in motion, but when driven at the proper speed the 

centrifugal force forces the oil to the periphery. This is what keeps 

the stone clean and sharp since the oil coming- from the interior 

lifts any gum or glazing 

from the surface. The, 

machines are equipped 

with two stones, one for 

rapid cutting, and the 

other for putting on a 

^smooth clean edge similar Fig. 54- AUTOMATIC KNIFE GRINDER 

to that of an oilstone. 

However, it is always better to complete the honing of the tool by 

hand. 

Kerosene oil is used on these machines and distributed evenly 
over the stone by means of the distributing devices into which the 
oil is dropped. Before the stones are used they should be thoroughly 
saturated with kerosene. After that little oil is required in grinding 
with the machine. 

58. Tool Rest-- The tool rest table has a groove running parallel to 
the face of the stone. The tool holder with the tool is shown in 
Fig. 53, and operates back and forth in this groove. 

59. Other Features - The grinding cone is for all concave edges such 
as gouges, cutters, curved tools, etc. The leather wheel back of the 
cone is so arranged that the edge of the leather projects and permits 
of stropping of the inside bevel of gouges. Straight edge tools are 
stropped on the face. After the edge tools are ground they may be 
stropped to give the finishing touches. However, care must be ex- 
ercised in using this stropping wheel and for the beginner it is ad- 
visable to use the bench oilstone and a hand strop. 

The emery wheel on the back of the machine is used for general 
grinding purposes. 

The wheels are protected by suitable guards and conform to the 
accident prevention laws. 

60. Saw Gumming- The attachment shown in Fig. 26 is necessary 



58 CARELESSNESS INFLICTS ITS OWN PUNISHMENT 

when using* the emery wheel on the back of the machine for saw 
gumming. A special wheel of the proper size for gumming is substi- 




Fig. 55- PORTABLE PLANER AND Fig. 56 — SHOWS FIG. 55 

JOINTER KNIFE GRINDER ATTACHED TO BED 

OF PLANER 

tuted for the regular emery wheel. The rest has two attached 
rams so that one can be locked at any desired angle. Locking it at 



CARELESSNESS INFLICTS ITS OWN PUNISHMENT 59 

a certain angle regulates the saw tooth; the second arm is pivotly 
counted on the first and carries the saw to and from the wheel. This 
ittachment may be used without interfering in any way with the other 
;wo wheels and the cone. When through gumming, this wheel should 
3e removed and the regular emery wheel again put in its place. 
6L Automatic Knife Grinding ~ The tool rest table is loosened 




Dimensions Sliowing- how Grinder can be 
adjusted to various maciiiiies. 



Fig. 57 LINE ETCHING OF ELECTRIE. PORTABLE, PLANER AND 
JOINTER KNIFE GRINDER. 

readily and swung down out of the way so as to make room for the 
automtic knife grinding attachment, Fig. 54. With this it is possible 
to grind all planer and jointer knives. Only the coarse stone is used 
for grinding these knives. In adjusting for grinding, be sure the 
the knifes DOES NOT RUN OFF THE STONE AT EITHER END 
OF THE STROKE, but let it advance to within one -half inch of each 
end and then start the reverse stroke. To get the best results from 
the sufacer and jointer it is necessary that exactly the same amount 
Df steel be removed from both blades when grinding them. In order 
to know whether or not they balance it is not well to guess at this 
but to use a knife balance which is just as sensative as that which 
is used by the druggist or in physical and chemical laboratories. After 



60 CARELESSNESS INFLICTS ITS OWN PUNISHMENT 

grinding use a hand oilstone to put on the finishing touches. 

62. Portable Planer and Jointer Knife Grinder. -The portable 
planer and jointer knife grinder in Fig. 55, makes it possible to grind 
knives on both circular and square cylinder heads in jointers and plan- 
er. The machine is attached by means of holes drilled and tapped in the 
base of the planer or jointers and is shown in Fig. 56. Also detail 
plan of the base section is shown in Fig. 57. The manufacturers 
of this machine urge that the knives be ground flat grind instead of 
hollow, suggesting at the same time that in using this machine the 
knife is held under the same strain while being sharpened as when 
in use, thereby eliminating the necessity of jointing after the machine 
has been taken from the clamp in the automatic floor grinder and 
again place in the cylinder head. The jointing of course, has a tend- 
ency to make a heavy heel which means more frequent grinding and 
consequently more wear and shorter life for the knife. However 
it should be stated that the casting which supports the motor is so 
constructed that it can be swung through a limited arc and locked in 
place so as to permit grinding on one edge of the cup wheel, giving 
aslight hollow grind as well as to have it in a verticral position, 
grinding square on both sides. It is also urged that in resharpen- 
ing knives by this method, that they remain always in place 
and alignment. This, of course, makes the machine cut faster and 
smoother and reduces the operating power. The graduated scale 
on the lowering device and beneath the handle insures uniformity of 
depth in grinding to a thousandth of an inch. The grinding wheel 
spindle has a ball bearing thrust which relieves, through universal 
coupling, all pressure from the motor armature and through its special 
take up bushing permits aperfectreadingofthemicrometerscale. The 
slide bearing which carries the motor has an adjustment with a scale 
on it that opeates on the bearing on one end, being slightly raised 
or lowered. By means of this adjutment, the bar can always be 
in perfect alignment when the knievs are set further on one end of 
the head than on the other. 



CHAPTER XI 



TRIMMERS 

63. General. Trimmers,- Figs. 58 to 62, were invented primarily for 
the use of pattern makers and when used for other processes should 
be used only after you have learned to preform these operations 
thoroughly and quickly by hand. This machine, like the miter saw, 
should not be used by beginners in order to avoid learning to do the 
various process by hand. Always take very thin cuts when using 
this machine. When working soft wood s" cut may be 
taken and if hard wood is used, the cutshouldnot be 
more than 1-16" in thickness. The machine must be 
kept sharp at all times if good results are to be ob- 
tained. The knives are very hard and in giinding 

should be ground with a 
very slight concave bevel. 
The back side must be 
kept perfectly straight. 

64. Operation- One of 
the smaller bench type of 
trimmers is used to ex- 
Fig. 58-TRIMMING INTO A c liKt K plain the operation and to 
show the possible range of work by means of auxiliary gauges which 
are furnished with most trimmers. Fig. 58 illustrates the trimming 
of a shoulder for either a half lap or a tenon. This is called trim- 
ming into a check. The gauge as well as the knife stands at an 
angle of 45 degrees, which makes it possible to trim down to the 
bottom leaving a square and smooth surface. 

Fig 59 illustrates the trimming of a wide miter. The trimming of 
a narrow miter on a regular piece of material is not illustated; how- 
ever, this is similar to that shown in Fig. 61. It is possible to miter 
a piece in this manner as wide as the machine will cut instead of 
simply as high as it will cut without the auxiliary gauge. 




62 SAFETY DEVICES ARE FOR USE NOT ORNAMENT 

Fig. 60 illustrates the cutting of a compound angle. A hopper 
shaped figure can be cut in this manner. The number of degrees 

at which the regular 
gauge of the ma- 
chine is set, swung 
away from 90 de- 
grees, regulates the 
slope which the 
sides will have, while 
the auxiliary gauge 
causes the angle to 
be cut at a miter 
Fig 59-TRIMMING A WIDE MITER thus making a regu- 

lar four sided figure. 

Fig. 61 shows a satisfactory method of trimming miters on crown 
or sprung moulding. A reverse pattern of the piece of moulding is 
first made 5" or 6" long and placed under the mould- 
ing while trimming. This pattern can be saved and 
used again. The auxiliary gauges used on the larger 
type of universal trimmer, P'ig 62, permits of larger 
work and is therefore mo. e valuble from the stand- 
point of utility. 






65. Mechanical Aids-Fig. 
63 shews the irgericis 
method in which the beds of 
some of the larger sty Its of 
trimmers are etched. The 
eccentric damning lever 
makes it possible to locate 
the swing gauges at any de- 
sired angle. The prominent 
angles, of course, are located by means of the taper spring stop pins 
and taper holes in the bed. 

The bed is laid out for 8-4-6-etc. segments to the circle and for a wide 
range of diameters. The radiating lines show the different numbers 



Fig 60-CUTTlNG A 
COMPOUND ANGLE 



SAFETY DEVICES ARE FOR USE-NOT ORNAMENT 36 



-OUTSIDE MITERS ON SPRUNG 
OR CROWN MOULDING 




FIG. 62- UNIVER 
3AL TRIMMER 



fosegm'ts while gradu- 
ations on these radiat- 
_^^ ing lines indicate the 
*^^ diameter which the 
__^^ complete circle will 
:^^^i^ have when segments 
are trimmed to that 
graduation. This illus- 
tration alsoshows a pat- 
ent stop rod for holding 
the segments in posi- 
tion for trimming. 
This is located at the 
desired graduation by 
fastening tw^o thumb 
screws. The segment 
should be long enoagh 
to allow for trimming 
at both ends. Since the 
head is so arranged 
that it may bedrawn 
back a short distace by 



64 SAFTEY DEVICES ARE FOR USE- 



-NOT ORNAMENTS 




Fig. 63 TRIMMING SEGMENTS 

means of a compression spring while the first cut is made. Then 
when the segment is Hfted to reverse ends, it is all ready 
for making the final cut, the head springs to its position. The 
bed is graduated on both sides which permits the use of either knife- 
Fig. 64 shows mechanical aids which are self-explanatory. 
Fig, 65 shows another etching which is also placed on the larger 
types of Fox Trimmers. This etching in Fig, 65 is primarily in- 
tended to illustrate the various number of degrees of a circle con- 
tained in a segment or triangle, and secondly, how to obtain the 
given diameter of a circle for a given number of segments with the 
aid of a scale and a pair of dividers. Explanation of use follows r 
As shown in Fig. 65 assume that it is desired to find the length of 
choid required for a circle 4" in diameter containing 6 segments of 
60 degrees each; set the dividers at 2 the radius of a 4 circle, place 
one leg of the dividers at the center of the gauge and the other in 



SAFETY DEVICES ARE FOR USE-NOT ORNAMENT 65 

l.,e to 60 ^^^':^l.:;^:::^^Z^ZT'Z resuU is the re- 
the intersection of 4 "^'^'^/^X.r knives require extreme care ,n 
quired chordlengtVi. The tnmmer Kn ^ ■ q^„A 

grinding, being much harder than °^dm"y m~ „ burned in 
Lwlv so as to avoid heatmgand d-v-8 the ' ™pe ^^^^^ ^^^ 

grinding, the only recourse IS to ?"7 f^';'°„„„t be retempered. 

To,-,n?r has not been drawn, since they cannoi ue 
in holg remember the caution expressed in Art. 63 



THE FOX MliCHIIIE CO. 

I TRIANGLE 

REGULAR 
POLYGONS 



^#I^^^^^RMIO RllPIOS.IIlCH.U.Si. 



TO fmO LtHGTll Of A CHOM) Or A SlVtH 
StOIIUlT.lULIlfir ITS RADIUS 
ev (ACTOR FROHCOlUilli. 

TO tiKO RAoms Of mscRi- 

RtO CIRClt. HUITIPIY 
SIOE Of SEGHtNT e» 
f ACTOR fROII 

coiuaii e. 




Fig. 65 



CHAPTER XII. 

DRYING AND STEAMING. 

67. General— The dry and steam box should be a part of every 
modern wood-working" shop where high grade cabinet work is done. 

These boxes are best madf' of iron with coils placed in the 
bottom of same. If the heating plant is available at all times, a 
live steampipe may be connected to these coils. Where this is not 
possible a gas heater can be installed for this special purpose. 

The drying box, of course, should be much lar.^or than the steam box. 
The drying box should open from the front so as to be opened the en- 
tire length for placing the long boards in the bcx. The steam box, 
of course, must be practically air-tight during operation. It is small 
er than the dry box and should open on one end only. The process 
of steaming is described in Art. 6S. 

It is to be understood that this dry box is not intended to be a 
dry kiln. Experience has shown that often when buying kiln dried 
lumber, it frequently acquires moisture while being brought from 
the shop and unless it is placed in a lumber room that is well heated 
satisfactory glue work does not result unless it is, at least, warn:ed 
after it has been prepared for gluing. For this reason the dry box 
is necessary for good results. 

68. Bending Wood and a Shop-made Steam Box— In selecting 
wood for bending only good "live" lumber should be used since 
lumber dried on the stump will not bend. It should be squared to 
size before bending since all that is done after bending is to clean it 
up and it is not possible to reduce the sizes materially without a great 
expenditure of time and effort after pieces have been steamed. 

A steam box like the one referred to in the preceding article is 
not always available and for this reason the simple steam box which 
is possible for any boy to make in the manual training shop or in his 



ACCIDENTS ARE CAUSED 67 

own shop at home will be described. Square the end of a piece of 
iron pipe or make a box 8 or 10" square (or larger) and of a length 
which will inclose the longest piece which you desire to steam. The 
ends of the pipe should be smoothed so that they can be closed by 
placing a large plug in them. When resting the box the end must be 
well squared up and the door or cover can be hinged, using burlap 
between the end and the cover, to keep the live steam from escaping. 

Where the box is to be used only once or twice, it is possible to 
nail the end in place but this soon makes the box unfit for use. 

A good teakettle may take the place of a steam generator. A 
small piece of pipe is inserted in the side or the top of the steam box 
and connected with the spout of the teakettle by means of a hose. 
In placing the steam box, one end should be slightly higher and 
at the lower end bore a very small hole so that the steam after con- 
densation may escape in the form of w^ater. Steam leaving the box 
in the form of vapor has not helped to soften the wood and is therefor 
wasted. For this reason do not crowd the teakettle. If any live 
steam escapes at the cover ov throught joints in the box, it is a good 
sign that you have too much heat under the teakettle. Fie sure in 
charging the steam box that the pieces are so arranged that the 
steam can readily get at all sides of each piece. Small pieces can be 
steamed in 20 minutes and are soft enought for bending. Large 
pieces require as much as several hours steaming before they are 
soft enought to bend. Perpare the form for bending by nailing 
blocks or brackets on the floor or on some bench-top especially pre- 
pared for this purpose. These blocks must all be ready for bending 
the piece to its proper shape before removing it from the steam box. 
Take the pieces from the steam box one at a time and place in the 
form quickly. If the piece is exposed to the air any length of time 
before placing in the form, it will not bend. Leave in a warm dry 
place until thoroughly hardened and dry before removing from the 
form. 

It is asserted by men of long experience that a steamed rocker 
is much stronger and more desirable than a sawn one. You will 
be surprised when making one of these steam boxes to find how 
simple, bending work really is. 



CHAPTER XIII. 

GLUE AND GLUE HEATERS 

69. General -- It is assumed that students using " Shop Notes" 
have previously learned how to make a glue joint by hand, hence, it 
will notnecessi *7 to repeat this information since the transition from 
a glue joint made by hand to the machine made glue joint is brought 
out in connection with the jointer. But many have had experience 
of preparing a good glue joint, and after gluing found that it does 
not hold. For this reason the manufacture of glue will be described 
and how to properly prepare it for use. This, of course, will be applied 
principally to hot glues, since the cold glue comes prepared ready for 
use. About the only information needed in connection with its use 
is that it must be kept covered when not in use, and should it become 
too thick, add a small amount of acetic acid, (vinegar). 

70 Glue And Its Preparation For Use - - Glue is of two kinds, animal 
glue and fish glue. Animal glue is made from bones, hides, feet, 
and trimmings of hides of animals. 

Salt is very destructive to glue since it attracts moisture. The first 
step in preparing glue stock is to remove the salt and foreign matter. 
In the case of skins and hides it is soaked in lime water. Materials 
that have bone, hoofs, etc. in them are leached in dilute acid solution. 

The stock is then boiled (very similar 
to the process of making soup) and the 
liquid (glutinous matter) extracted (call- 
ed a run) is treated with preservatives, 
boiled down and dried. The stock may 
be used a number of times. 

Fish glue is made from fish waste 
comprising skins, head, fins, tails, scales, 
and bones. The salt is removed by agitat- 

FiG. 66 -MIXER AND GLUE HEATER ^"^ ^his raw material in cold water for 
SHOWING CONSTRUCTION. several days before boiling. The gluti- 






OVERFLOW 




QUALITY FIRST—THEN QUANTITY 



69 



nous matter is then treated in the same manner as the animal s\ue. 

Liquid, sometimes called cold glue, may be made from either fish 
or animal glue. The liquid glue cans should always be kept closed 
when not in use. Should it become too thick or heavy, add a little 
acetic acid or vinegar. In cold waether, by placing in a hot bath 
or a warm place. 

To prepare hot glue, break it into small pieces and soak for 12 
hours in cold water before boiling. Always use a glue pot of the 
double boiler type, one of which is shown in Fig. 66. This has a 
mixer as well as the seperate glue pots in which the glue is afterwards 
placed. It should be the consistency of thin syrup when applied. 

The best glue is of a clear amber color and free from spots. 
A small wooden paddle makes an excellent spreader. 
71. Glue Hearers--The glue heater shown in Fig. 66 may be 
attached to a live steam pipe so as to heat the water for preparing 
the glue and keeping it heated, ot^ have gas burners placed beneath 
it. In mixing glue, always keep, in mind that glue which has been 
heated very many times loses its strength. For this reason no more 
should be mixed at a time than can be used with minimum number 
of re-hearings. 

Fig. 67 illustrates a water jacketed 
3-heat pot. These are made for both from 
95 to 125 volts and for 200 to 250 volts, the 
the latter type of glue pot being more ex- 
pensive. They are made in various sizes, 
but usually 1, 2 and4 quart sizes. Pots are 
usually equipped completely with 3 terminal 
contact plug, with a cable and a 3-heat wall 
receptacle. 

Fig. 67-- three-heat 
water jacketed electric 

GLUE POT 




CHAPTER XIV 

EXHAUST SYSTEMS. 

72. Exhaust Systems - A mill room in order to be modern and com- 
pletely equipped should have an arrangement for carrying out the 
dust along with shavings, chips, saw-dust, etc., from the different 
machines while in operation. The arrangement for this purpose is 
called an exhaust system, and consists of a system of pipes leading 
from the different machines in the shop to one large outlet pipe, at 
the end of which is an exhaustor fan which draws out the dust, etc , 
already mentioned. It drops into an incinerator, or by means of 
additional pipes is carried to the boiler room where it is used as fuel. 
It will be an interesting, as well as a profitable, visit for you to go 
to a modern up-to-date planing mill and see just how the exhaustor 
system is installed and how it is operated. 

A few fundamental facts should be kept in mind. The outlet pipe 
must be full size until the shavings reach the incinerator or the point 
where they leave for the boilor room. The intake pipes which lead 
from the machines to the outlet pipe are smaller ( their combined 
area must not exceed that of the outlet pipe ), and the size is de- 
termined by the machine which they serve, for instance: the planer 
depending upon the size requires a 4 or 5" pipe, while the saw re- 
quires 3" or smaller. For a school mill room a system having a 12" 
outlet pipe is ample. This can be operated with a 24" fan. 

73. Speed and Power -- The 24". fan just referred to, in order to give 
efficient service, must run at a speed of 2500 R. P. M. and will require 
a 5 h. p. motor. 



CHAPTER XV 

POWER TRANSMISSION 

74. General— Belting is the oldest agent for power transmission and 
still proves to be most effective in spite of the fact that many other 
agents and devices have been worked out in the last few years. 
Where belting is not serving effectively for power transmission it is 
nearly always due to one of two reasons which can readily be re- 
moved. Either an inferior grade of belting is used or the belting 
does not receive proper care and attention. 

Only the best grade of leather belting (single and double ply) 
should never be used. The canvas and so-called rubber belting 
should ever be advocated where wear and service is desired. The 
best grade of belting is always the cheapest in the end because it 
not only lasts longer but costs much less for upkeep. Machines are 
idle while belts are being repaired this is an expensive proposition. 

Every plant should have someone in charge of the belts and no 
one should be' allowed to work on the belts or make any changes in 
them except under the supervision of the belting man. This is being 
done in large plants commanded by efficiency experts but is also pos- 
sible for the small plant because it does not necessarily follow that 
this man need spend his enti'e time looking after the belts. The 
one in charge of this work should be a person who has been special- 
ly trained either in the factory where he has had experience in the 
manufacture of beiting or as an apprentice under a belt specialist. 

School shops will do well to adopt this shop practice in order to 
make the work real. To make this effective, belt records, which are 
to be had for the asking from large manufacturers of belting such 
as Graton-Knight Manufacturing Company of Worcester, Massa- 
chusetts, should be kept systematically. The belt should be periodi- 
cally inspected so as to determine whether or not it has become too 
dry, saturated with oil, over-treatfd with belt dressing, opening up of 
laps, etc. 



72 RESPECT THE MACHINE OPERATOR 

Do not talk to him while he is operating: a machine 

75. General Care — B^lts, in order to render the most effective ser- 
vice and wear as long as possible, should, at all times, be kept soft 
and pliable. To do this, too much grease and mineral oil should be 
avoided as they rot the leather. (Particularly isthist'"ue of the miner- 
al oil.) 

Whe'' a belt has become too dry, the surface should first be cleaned 
by rubbing with a cloth dampened with kerosine. Then apply a thin 
coat of Neat's Foot Oil to each side of the belt. Apply a second coat 
and as many more as are necessary to give the belt that mellow feel- 
ing which is characteristic of a good working condition. This should 
be repeated monthly for a belt which sees hard service. There are 
specially prepared compounds put out by the standard manufacturers 
of belting supplies that have nothing in them which is injuri- 
ous to leather and are said to be better than the Neat's Foot Oil. 

Grease and oil is not only injurious to the leather, but cause friction, 
thereby wasting power. Belts must always be protected from the 
oil wherever possible, but where this is impossible, they should be 
cleaned periodically with naphta or carbon tetrachloride. 

Oil also injures the sticking qualities of ordinary cement and is the 
cause of laps beginning to open at the points. Once the lap begins 
to loosen at the point it should be repaired by first removing the oil 
and then gluing. Driving tacks through the joint or a heavy cast 
iron belt fastener weakens the piece of leather ai'd causes a bump of 
the belt every time the piece of metal goes around the pully. 

Always use sticky belt dressing very sparingly and then only when 
absolutely necessary. Sticky belt dressing if used to a consderable 
extent sticks the pully to the belt so .tightly that it pulls the grain 
off the belt, works into the leather causing it to rot. If the pulleys 
are properly lined up the belts will stay on and a preservative is 
very much to be preferred to a sticky belt dressing. 

76. Splicing (Wire, Whang, Bait hooks and Glue) — Belts may be 
spliced in a number of ways. However, thereisonly one really effic- 
ient method for splicing belts, and that is to glue them. 



RESPECT THE MACHINE OPERATOR 73 

Do not speak to him while he is operating a machine * 

Belt hooks are sometimes used and are perhaps to be recommend- 
ed for cheap rybber belts which are sometimes used on farm machin- 
ery. 

Raw hide or whang lacing is often used to advantage when belts 
are run at a low speed; but this usually causes a noise referred to as 
"pounding" which is not desirable; and it must be remembered that 
lacing reduces the strength of the belt ane-third at the splice. To 
somewhat reduce the pounding at the' joint, wire lacing may be 
used which, although not noiseless is less noisly than the whang lac- 
ing. It is quite satisf factory on pulleys of large diameters but has a 
tendency to break when used on very small ones. This makes it 
dangerous if used for lathe and other small pulley belts that must 
be shifted by hand. Where a large number of belts are kept up by 
the use of wire lacing, a machine is used which makes it possible to 
splice by means of wire lacing very quickly. The endless or glued 
belt, as already stated, is the most satisfactory and particularly is 
this true of high speed machines since the splicing is noiseless. 

The two types of endless belts are shown 
^ , OH Or v^o^o^H ' -^ pi^^ 68, and are known as single and 

> ■ ""^"-^ — "> ^ --'^- — ^double ply splices. Preparatory to splic- 

^^ ing, the ends of the belt should be planed 
Fig. 68 SINGLE AND DOUBLE back as far as the belt is wide. In other 
PLY SPLICES words, the lap should be square. Place 

together on a board so as to use one edge as a straight edge in order 
to keep the edge of the belt straight. Otherwise one side of the 
belt will be made to assume more than its part of the strain in use. 
Apply a coat of belt glue very much the sam.e as in gluing wood. The 
glue should be about the consistency of thick syrup. After the laps 
have been put together use a hammer working from center out in 
order to work out any surplus glue. Place a piece of paper on the 
joint and then apply a wood hand clamp to hold it in place. It is best 
to leave it from two to six hours before using; although some manufac- 
turers insist that when their glue is used, belts may be used after 
haviing set for from one-half to three-quarters of an hour. When 
gluing a belt, the lap of which is larger than the hand clamp will 



74 



RESPECT THE MACHINE OPERATOR 

Do not speak to him while he is operating a machine 




cover, place a board over the joint and then clamp over this and the 
board on which the belt is resting. With very large belts, a portio 
of the joint must be glued at a time since chilled glue positively has 
no sticking qnalities. It sometimes happens that a belt must be put 
on the pulleys before gluing. Where this is the case a belt clamp 
and rods is necessary. The 
belts are drawn over the 
pulleys but care must be 
exercised to have them so 
that the hide or grain side 
will run next to the pulleys 
and so that the points of the 
lap will run against the pull- 
eys. The lap on the outside Fig. 69 BELT CLAMP AND RODS 
of the belt is likely to come loose if run against the air pressure 
(see Fig. 68). The general instructions are the same. ()utside of 
this exercise care in drawing up the rods, making a final test just 
before gluing. If in this test you find it necessary to draw up 
either one of the rods so as to bring it into line, refit the lap before 
gluing, if necessary. The board previously mentioned in this case 
should be wide enoagh to go between the rods and long enough to 
extend under the entire lap. It may be strapped to the rod in such 
a way that you can shave the lap down and fit it. 

Figs. 70 to 73 illustrate the simple method of using wire lacing. 

The ends of the 
belt should first 
be squared and 
the holes 
punched oppo- 
site each other 

Fig. 70 SIMPLE METHOD OF LACING. Fig. 71 and Only as far 
back from tiie end as ihe thickness of the belt. The distance apart 
should be so that approximately 9 holes are punched for evp*-y !" 





PULLEY SIDE 






A C 


E 


• 


• i 


• 


• 


• 


• « 


• 


• 




6 D 


F 




RESPECT THE MACHINE OPERATOR 

Do not speak to him while he is operating a machine 



75 







PULLEY SIDE 

ACE 


1 












1 
















E 


) C 


) F 






of belting. The ends of the belt are placed tog-ether for lacing and 
to hold them steady, binders should be placed in the holes nearest 
the edges of the belt. A piece of lacing seven times the width of 
the belt should be used for the single and nine times the width of 
the belt for double. Wire should be inserted over the pulley side 

beginning with 
the holes near- 
est the center 
of the belt as 
shown in figure 
70. Double 
lace this hole ag 
F!g. 72 Fig. 73 ^^lown in figure 

70 and 72 and cross to the next holes towards the outside of the belt 
as shown in figure 71. Use pliers to draw the ends of the wire up 
tight, but do not stretch. Double lace each side of the holes keep- 
ing the holes straight strands on the pulley side. Remove the binder 
and double lace on both outside holes and run the end of the wire a- 
cross to the next hole on the pulley side as shown in figure 72 and 
bring up on the outside of the belt, cut off i" and flatten the ends 
down as shown in figure 73. After lacing in this manner, hammer 
down flush with the pulley on the pulley t^^ide. Rubbt-r belts are 
laced in the same manner, but a belt awl is used instead of a punch: 
Sizes for wire lacing are as follows: 

No. 00 For light single belts up to 1". 

No. For single belts under 3" wide. 

No. 1 For single belts 3" to 5" wide. 

No. 2 For wide single and narrow double belts. 

No. 3 For all double belts above 6" wide. 

There are several styles of lacing a belt when using whang or 
lacing leather. The chart shown in figure 74 gives ihe proper sizes 
for punching holes. Large lacing holes and excess lace are harmful 



76 



RESPECT THE MACHINE OPERATOR 

Do not speak to him while he is operating a machine 



and should be as religiously avoided as the iron belt clamps an tacks. 

In squaring the belt for lacing always cut, using a try square. The 

holes in both ends of the belt should be exactly opposite and no hole 

should be less than J" from the edge of the belt nor nearer the end 

than i". The holes 
should be placed ap- 
proximately I" from 
center to center. For 
width of lacing and the 
proper sizes of holes 
for the various widths 
of belting, see chart, 
figure 74. 

Lacings come in bun- 
dles of 100 feet and 
varies in width. These 
lacings are very strong 
and the best ones are 
made from imported 
India cow hide taken 
from the hides of young 
animals so as to secure 
freedom from grubs, 
cuts, and other imper- 



Punch 


Diam. of 


Recom'd 
Width of 


Width 
of 


Weight 
of 


Number 


Hole 


Lace 


Belt 


Lace 


6 


11 
64 


'4 




Light 


7 


3 
IG 

1 

4 


5 


^ Up to 5 

1 




8 


16 




Light 


9 


9 
32 


% 


1 
1 


Medium 


10 


5 

16 


7 
16 


;-6 to 14 


Medium 


11 


3 

8 

13 


1/ 


J 


Heavy 


12 


32 


% & % 


14 & over 


Heavy 



Fig. 74^ LACING SPECIFICATIONS 
fections. The lacing from i" to 5-16" 
are known as light weight and 3-S" 
to 7-16" as medium. Larger sizes 
than these are designated heavy. 
The style known as the straight 
stitch lace figures 75, 76, 77 and 78 
will first be described. Figure 75 

Fig 75- STRAIGHT STITCH LACE FOR 
ODD NUMBER OF HOLES 




RESPECT THE MACHINE OPERATOR 

Do not speak to him while he is operating: a machine 



77 



shows a lace for an uneven number of holes, (a) The lace is first 
placed through the central holes, 3 and 8, then draw the ends even 
as shown in the illustration. Next put No.l up through No. 3 and 
down through No. 8 so as to double lace the center. Next put it 





Fig. 76- FLESH SIDE FOR Fig. 77- GRAIN SIDE FOR 

ODD NUMBER OF HOLES ODD NUMBER OF HOLES 

through No. 4, down through No. 9, up through No. 5, down through 
No. 10, up through No. 5, down through No. 10, up through No. 4, 
down through No. 9, and up through No. 3. Punch holes with belt 
awl and then fasten directly back of hole No 3, as shown in Fig. 76 





Fig. 78- BEGINNING LACE 
FOR EVEN NUMBER 
OF HOLES 



Fig. 79- HINGE LACE LOOK 

SAME ON BOTH SIDES OF 

THE BELT 



78 



RESPECT THE MACHINE OPERATOR 

Do not speak to him while he is operating a machine 



and 77 (b) Next put lace No. 2 up through hole No. 7, down through 
No. 2, up through No. 6, down through No. 1, up through No. 6, 
down through No. 1, up through No. 7, down through No. 2, up 
through No. 8 and fasten same as No. 1. This order applies to any 
uneven number of holes and no difficulty will be experienced if you 

begin with, the center holes. 

When a belt is 
of a width requir- 
ing an even num- 
ber of holes begin 
as shown in Fig. 
78. Then put lace 
No. 1 down thru 
hole No. 7, up 
thru No. 4, down 
through No. 8, up 
through No. 4, 




c 


r„,n d.1t 


,o 


eO jO 


.o 


^P 


/ r\ \ 


.Oi 


IL ^ 


,p/ 


„o ^ 




\ Grc.. Arfe 



Fig. 80. — Hinge Joint Avoids 
Stiff Lace 



Fig. 81. - 

Hole 

punched and 

beginning of 

lace for 

hinge lace. 



Continued next page. 



77. Belting Rules. When using pulleys of equal, or nearly equal 
size without idlers and the arc of contact is 180° each, the following 
formula may be used to determine the proper belt to be used. 

Speed in ft. per min. (S.F.P.M.)=: pulley diameter in ft. x 3. 1419 x R.P.M. of 
pulley. 

H.P. — (S.F.P.M.)x width of belt in inches x 55. (working tension or effective pull) 
product divided by 33,000 and the quotient will be for single belt. The result 
obtained for single belt if multiplied by 1.6 will give the result for double and if 
multiplied twice for three-ply belting. 

The width of belting: =:Given H.P. x 33,000 product divided by product of belt 
speed in feet per minute x 55 for single belts; 88 double; three-ply 110 (working 
tension or effective pull). 

In the rule just given the 55 for single belts; 88 for double; and 110 
for three-ply is the "working tension or effective pull" where the 
arc of contact is 180°. Continued on page 81. 



RESPECT THE MACHINE OPERATOR 79 

Do not speak to him while he is operating a machine 

down through No. 8, up through No. 3, down through No. 7, and up 
through No. 2. Then with a belt awl, punch a hole and fasten di- 
rectly back of No. 2 as in Figs. 76 and 77. Then put lace No. 2 
down through hole No, 2, up through No. 5, down through No. 1. 
up through No. 5, down through No. 1, up through No. 6, down 
through No. 2, up through No. 7 and fasten in the same manner 
back of hole No. 7. In this case only four holes to a row were used. 

However, the same instructions apply when using any even num- 
ber of holes. 

In order to lace for "hinge" plan, as shown in Figs. 79 and 80, 
punch the ends as shown in P'ig. 81. Put the lace through No. 5 
and draw ends even. Then put the ends of the belt together and 
pass each strand of the lace between the ends of the belt as shown 
in figure. Then pass No. 1 lace up through No. 8, down between 
ends of belt, up through No. 5, down through No. 2, up through 
No, 5 and down between ends again. Put lace No. 2 down through 
No, 8, up through No. 11 down through No. 8, up between ends. 
down through No. 4, up between ends, down through No. 7, up be- 
tween ends, down through No. 4, up through No. 1, down through 
No, 4, up between ends, down through No, 7, up through No. 10, 
down through No. 7, up between ends, down through No. 4, 
up through No. 1. Punch hole with belt awl and fasten directly 
back of No. 1. Reverse this process in lacing through half of the 
belt, fastening the ends of the lace back of hole No. 12. These in- 
structions apply for any odd number of holes to the row. When 
the width of the belt requii'es an even number of holes to the row. 
begin with either one of the two center holes, and follow the same 
instructions. 

78- DRIVE AND SPEEDS. 

78 a- Drive. 

The drive as a rule, consists of the pully which transmits the power 
to the belt. However, in some cases it is directly connected by means 
of a friction clutch or a flexible coupling, to the machine that is to be 
driven. In the case of a gear drive a chain is used instead of a belt. 



80 RESPECT THE MACHINE OPERATOIl 

Do not talk to him while he is operatinpr a machine 

78 b-The Driven. 

This usually applies to the pully to which the power is transmitted 
from the drive. However, in the case of the direct drive it would be 
the shaft, or, the pully on the friction clutch which operates the ma- 
chine. 

78 c-Speed. 

The term speed has reference to the number of revolutions made 
by the pulley per minute, and is designated by the letters R.P.M., 
meaning- revolutions per minute. 
78 d-Rules for Speeds of Pulleys. 

The diameter of tiie driving pulley (D) multiplied by its speed (S) 
is equal to the diameter of the driven (d), multiplied by its speed (s) , 

Surface speed, also referred to as cutting speed in connection with 
the turning lathe, saws, etc., refers to the number of lineal feet 
measured on the surface of ihe work that pass the cutting edge of 
the tool in one minute, 

78 d-Rules for Surface Speed. The number of feet in the circum- 
ferance of the work or the tool being turned, multiplied by the 
number of revolutions per. minute gives the surface speed in feet 
Ijer. minute. 

78 e-Formula for Speed of Pulleys. If D represents the diameter 
of the driving pulley and d represents the diameter of the driven 
pulley, S, the speed of the driving pulley, s the speed of the driven 
pulley, then DS equals ds. For cutting speed, if C equals the cut- 
ting spaed and c equals the circumference of the work or ihe tool 
that is cutting, then c x R. P. M. equals C. 

For example, a 36" Band Saw with a 12" drive pulley to be run 
from 500 to 600 R. P. M. is being installed. A 3 horse power motor 
with a speed of 1800 R. P. M. is to be used for the drive. What 
size pulley will be needed on the motor? 

Substituting in the formula DS equals ds. We have I) x ISOO equals 
12 X 600. 12 X 600 equals 7200 divided by 1800 equals 4 or D, the 
size of pulley neccessary to drive the Band Saw at its proper speed. 



RESPECT THE MACHINE OPERATOK 

Do not speak to him while he is operating a machine 



81 



78f. Exercises. 1. Find the cutting speed of the band saw in the 
preceding paragraph. 

2. Measure the drive and driven pulleys on the saw table and find 
the R. P. M. of the saw arbor? What is the surface speed each for 
a 10" and a 12" saw when run at this speed? In using speed indi- 
cator, Fig. 86, what do you find to be the R. P. M. of the saw arbor? 

3. Substitute the swing saw for the saw table in problem 2 and solve. 

4. Verify the speeds of the other machines in the shop. 

5. Instructor will dictate lists of problems providing local application 
of formula and rules in Arts. 77 and 78. 




Fig. 83- BELTING SPECIFICATION 
SKETCH 



Continued from page 78. 

To find the working ten- 
sion or effective pull when 
arc of contact is not 180°; 
multiply arc of contact x 155 
for single belt, 88 for doub- 
le, and 110 for three-ply and 
divide this product by 180. 

To find arc of contact. Fig. 
82, draw line or tape over 
pulleys as indicated and use 
protractor to find number of 
degrees. 

When ordering belting in 
large quantities it is advis- 
able to consult the manufac- 
turer and send in sketch as 
shown in Fig. 83. The 



length may readily be obtained by drawing a tape over the pulleys 
in the position the belt will assume when in use. The length neces- 
sary for lap. Fig. 84, varies with the width of the belt, and should 
be as long as the belt is wide. 

To find the number of feet of belting in a roll, divide the diameter 
of the roll by 2, multiply by 3 1 '7, and this result by the number of 



82 



RESPECT THE MACHINE OPERATOR 

Do not speak to him while he is operating- a machine 



;au-ow for 
• FOX L^y 



'f- : NET DisTAMct AROUND PULLEYS >! colls lu the roll. If therc is a hole 

— "^ at center of the roll, add its 
diameter to the outside diameter 
before dividing by 2. 
Fig. 84— BELT LENGTH Common drivers are represent- 

ed and named in Fig, 85. 





No. I OPEN DRIVE— SLACK ON TOP 





No 2 OPEN DRIVE— SLACK ON BOTTOM 




No i OPF.N DRIVE -WITH FIXED BINDER 



7, Quarter turn to left; 8, Quarter turn to 

right; 9, Four pulley quarter-turn drive; 

10, (Elevation and plan, ) Three pulley quar- r—^ 

ter-turn drive; 11, (Elevation and plan) ^ 

Mule Drive; 12, Lenix Drive. no. 6 crossed-belt drive 




Fig. 85- COMMON DRIVES 



RESPECT THE MACHINE OPERATOR 

Do not speak to him while he i. operating a machuu. 



83 




Fig. 86 Sl'KKU INDICATOR 



CHAPTER XVI. 

WOODWORKING AND GENERAL SAFETY ORDERS. 

79 Safety Provisions of the Workmen's Compensation, Insurance 
and Safety Act, Chapter 176 of the Law of 1913. 

Sections 51 to 72, inckisive, of the Workmen's Compensation, In- 
surance and Safety Act give the Industrial Accident Commisson power 
to make and enforce safety orders, rules and regulations, to prescribe 
safety devies, and to fix safety standards. It also empowers the 
Commission to appointadvisors whoshall, without compensatioit, assist 
the Commission in establishing standards of safety. The Commission 
may adopt and incorporate in its general orders such safety rec- 
ommendations as it may receive from such advisors. 

As a result of this, the commission asked various allied interests 
to serve on sub-committees to draft the Wood Working Safety Orders. 
The sub-coinmittees were not named until the commiltee on General 
Safety Orders had organized in San Francisco and Los Angeles had 
been consulted. The General Safety Orders Committees prepared 
the General Safety Orders which went into effect January 1st. 
These committees prepared the orders which follow under separate 
Arts, and which have been effective since August 1st, 1916. 

80. Circular Rip Saw. Order 600. All circular saws must be guarded 

■by hooded guards and must be provided with spreaders or splitters 

and or dogs, which shall be located at the rear of the saws. Guards 

must also ba provided to prevent contact with that part of the saw 

which is underneath the table. 

Exception. Where special w'ork is being done, such will nrevent 
the use of a guard and orspHtter ordogs, such guard and or splitter 
or dog may be omitted, but in case where such special work is 
temporarily carried on, a guard and or splitter ordogs must be provi- 
ded and put in place during all operations other than that involved in 
special work. 

81 Crosscut Saws. Order 600. (a) All crosscut saws of the swinging 



SAFETY FIRST AND ALWAYS 85 

type must be guarded. Knuckle guards must be attached to the swing 
frame, (b) All swing cut-off saws must be provided with a device 
which will return the saw to the back of the table and prevent a re- 
bound, (c) Means shall be provided on swing cut-off saws to pre- 
vent the counterweight throwing the saw forward into the travel, 
(d) The rear side of crosscut swing saws must be guarded, (e) All 
circular crosscut saws must be guarded by hoods where the saws 
are held on fixed horizontal bearings. 

82 Band Saws. Order 602. 
(a) Guards must be installed to cover both upper and lower wheels 
of all ba'id saws. 

The up-travel of all band saws must be completely guarded, and 
the down-travel must be guarded with a shield extending down to the 
guide rolls. 

83. Wood Jointers. Order 603. 

(a) All wood jointers must be equipped with cylindrical cutter 
heads of the safety type. 

(b) A suitable automatically adjusted guard must be placed over the 
whole cutting space in the table. 

84. Sanding Machines. Order 604. 

(a) Disc sander must have the circumference and back of the revol- 
ving head thoroughly guarded. 

(b) Belt Sanders must have both pulleys enclosed. 

85 Mortising Machines Order 605. 

(a) Thumb guards must be provided on all mortising machines, to 
prevent the hands of the operator fi'om coming in contact with the 
chisel except on mortising machines of such type thatitis not required 
to use a clamp which would bring the hands of the operator into close 
proximity to the cutting edge. 

86 Shapers Order 606 

(a) All knife heads of wood shapers and similar heads of other 
machines, not automatically fed, must be guarded, or forms must be 
used in which the part operated on is securely fastened. 



86 SAFETY FIRST AND ALWAYS 

Exception. Where special work is being done which will prevent 
the use of a guard, said guard may be omitted, but in cases wiiere 
such special work is temporarily carried on, a guard must be provid- 
ed to put in place during all operations other than that involving 
special work. 

(b) All knife heads of woodworking machines which are auto- 
matically fed, such as stickers, planers, etc., when exposed to con- 
tact, must be guarded. 

87. Tenoning Machines. Order 607. (a) Cutting heads and saws 
of tenoning machines must be guarded. 

88. Lighting. Order 608. (a) Ample light, either natural or arti- 
ficial, must be provided around woodworking machinery. 

89. Gears, etc. Order 609. (a) All gears, belts, pulleys and sprock- 
ets and shafting connected with woodworking machinery, shall be 
guarded in accordance with the General Safety Orders issued by the 
Industrial Accident Commission. 

90. Multiple Unit Drive. Order 610. (a) Where practicable, not 
more than ten machines shall be driven in one unit. Where a great- 
er number than ten machines are driven from one line shaft, a clutch, 
tight and loose pulley shifter, switch, idler or other mechanical 
means shall be provided in that room or department which will im- 
mediately stop all machinery in that group. 

NOTE. —The prompt stoppage of machinery in emergencie« is hastened by al- 
lowing the full load to remain on al' machines. It is of vital importance that a 
proper starting and stopping device be provided in the room or department in ca- 
ses where engines or motors are located in another department or in another build- 
ing. 

91. Recommendation. It is recommended that floors where oper- 
ators stand to operate machines, such as wocd-shapeis, jointeis, 
saws, etc., should be provided with nonslip surfaces and kept clear 
of waste material. 

GENERAL SAFETY ORDERS 

92. Gears. Order 1. (a) All gear.s, where exposed to contact, 
must be entirely enclosed, or equi])ped with .^ide tlange.s extending 
inward bevond the root of the teeth. 



SAFETY FIRST AND ALWAYS 87 

(b) All spoke gears and open web gears, which are over eighteen 
(18) inches in diameter, where exposed to contact, must be entirely 
enclosed. On large gears, such as those on heavy shears and punches, 
the guard must be such as to cover them to a height of seven (7) 
feet above the floor. 

(c) Where it is clearly impracticable to cover gears, as described 
above, a boxed frame of metal or wood must be installed, completely 
shutting off the machinery gears. 

(d) All gear guards must be kept in place while the machinery is 
in operation. 

93. Belts. Order 2. (a) All belts, ropes or chains driving ma- 
chinery or shafting, and all secondary belts, ropes or chains where 
exposed to contact, must be guarded. In all cases the point where 
the belt, rope or chain runs on to the pulley, sheave or sprocket, if 
within seven (7) feet of the floor or platform, must be guarded. 

Exception : Belts which are so small or so slow moving that they 
are not in any way a source of danger. 

(b) All horizontal belts, ropes or chains driving machinery or shaft- 
ing, seven (7) feet or less above the floor or platform, where exposed 
to contact, mUst be guarded. All overhead belts six (6) inches or 
more in width and over seven (7) feet from floor or platform, must 
be guarded underneath and on sides, .unless so guarded that persons 
can not pass under them. All chain or rope drives over seven (7) 
feet from floor or platform must be guarded in like manner to belts 
over six (6) inches in width. In all cases the guard should cover the 
outer faces of the two pulleys or sheaves and extend upward to such 
a point, and be attached in such a way, that in case the belt, chain 
or rope breaks, the guard will withstand the whipping force. 

(c) Vertical and inclined belts must be substantially guarded as 
follows : 

1. If the guard must be less than fifteen (15) inches from the belt, 
with a complete enclosure of wood or metal to a height of six (6) feet 
above the floor. 

2. If the guard can be placed within at least fifteen (15) inches 
clearance from the belt, with a tvi^o-rail railing at least three and 
one-half (3>4) feet high. 

Note. — In rooms, or parts of rooms, used exclusively for transmission machinery, 
such as the ground floor of sawmills and the basements of |)aper mills or flour mills, 
it has been found practical to define certain passageways for the use of oilers and 
millwrights, and to guard the pulleys, belts and shafts along these passageways. 

94. Pulleys. Order 3,. (a) Pulleys must be so placed as to allow 
the width of the belt between two pulleys, or between the pulley and 



88 SAFTEY FIRST AND ALWAYS 

the shaft hanger or bearing, or a hook must be provided, or a guard 
placed adjacent to the pulley to prevent the belt from leaving the 
pulley. 

(b) All machines must be equipped with a loose pulley' or a clutch 
or some other adequate means of stopping the machine quickly. 

(c) All pulleys or parts of pulleys within seven (7) feet of the floor 
must be guarded, if exposed to contact. 

95. Clutches. Order 4. (a) All clutches must be completely 

Note. — Pfactically all clutches have protruding parts which make them as dan- 
gerous as projecting set screws on shafting. 

guarded where exposed. 

96. Belt Shifters. Order 5. (a) A permanent belt shifter must be 
provided for all loose pulleys, and must be located within easy reach 
of the operator. The construction of belt shifters must be such as to 
make it impossible for the belt to creep back onto the tight pulley. 
All belt shifters must be equipped wath a lock or some other device 
to prevent accidental shifting. 

97. Shafting. Order 6. (a) All transmission shafting, either hori- 
zontal or vertical, in workrooms or in passageways leading to work- 
rooms, and located within seven (7) feet of the floor or platform, must 
be guarded. . 

(b) Dead ends of shafts less than seven (7) feet from the floor or 
platform, or wherever exposed to contact, must be guarded. 

98. Set Screws. Order 7. (a) All projecting set screws on moving 
parts must be removed, countersunk, or protected by a solid collar, or 
a headless set screw must be used. No part of the set screw must 
project above the surface. 

99. Sprockets. Order 8. (a) All sprockets must be guarded, if 
.exposed. 

100. Flywheels. Order 9. (This applies to flywheels of machines 
and not to flywheels of engines, which must be guarded in accordance 
with Safety Orders for Stationary Engines.) 

x^ll parts of flywheels with spokes, which are seven (7) feet or less 
above the floor, must be guarded as follows : 

(a) If guard is at least fifteen (15) inches in the clear from b(Uh 
sides and face of wheel, a fence may be used at least three and one-half 
(3^/4) fee't high, to be either solid or of substantially supported wire 
mesh or close slats.. 

(b) If guard is less than fifteen (15,) inches in the clear from both 
sides and face of wheel, a fence must be provided at least five (5) 
feet high, the fencing to be either solid or of substantially supported 



SAFETY FIRST AND ALWAYS 



89 



wire mesh or close slats. 

Exception: Flywheels which are so small, or so slow moving that 
they are not in any way a source of danger. 

(c) All flywheel pits must be surrounded with a toe-board not less 
than six (6) inches in height. 

101. Grinding Wheels. Order 10. (a) Where practicable, grinding 
wheels must be provided with a hooded guard of sufficient strength 
to withstand the shock of a bursting wheel This guard must be 
adjusted close to the wheel and extend forward over the top of the 
wheel to a point at least thirty (30) degrees beyond a vertical line 
drawn through the center of the wheel. 

(b) Arbor ends must be guarded. 

(c) Speed of wheels must not exceed the speed guaranteed by the 
manufacturer. 

(d) Where practicable, grinding wheels must be provided with 
safety flanges. 

Note. — Wheels should be handled with the greatest care in unpacking, storing, 
delivering, etc., and should never be left standing on the ground or wet places. 
Great care should be used in mounting wheels ; never force a wheel on the arbor. 
It is advisable to use relieved flanges, compressible washers between wheel and 
flange, and to obtain a perfect bearing at the outer edge of the flange. Vibration 
• should be avoided at all times. 



Diameter of wheel in injhes 


Revolutions 

per minute 

for surface 

speed of 

4,000 feet 


Revolutions 

per mniute 

for surface 

speed of 

5,000 feet 


Revolutions 

per minute 

for surface 

speed of 

6,000 feet 



1. 

y 

i.. 

4.. 

5.. 

6.. 

7.. 

S.. 
10.. 
12.. 
14.. 
'6.. 
18.. 
20.. 
22.. 
24.. 
26.. 
2S.. 
3Q. 
32.. 
.•?4. 
36.. 



15,279 


19,099 


22,918 


7,639 


9,549 


11.459 


5,093 


6,366 


7,639 


3,820 


4,775 


5,730 


3,056 


3,820 


4,584 


2,546 


3,183 


3,820 


2,183 


2.728 


3,274 


1,910 


2,387 


2,865 


1,528 


1,910 


2,292 


1,273 


1,592 


1,910 


1.091 


1,364 


1,637 


955 


1.194 


1,432 


849 


1.061 


1,273 


/64 


955 


1,146 


f94 


868 


1,042 


637 


796 


955 


586 


733 


879 


546 


683 


819 


509 


637 


764 


477 


596 


716 


449 


561 


674 


424 


531 


637 



Table of Grinding Wheel Speeds 

The revolutions per minute at which wheels are run is dependent 



90 SAFETY FIRST AND ALWAYS 

on conditions, and in actual practice wheels are run at surface speeds 
of from 4,000 to 6,000 feet per minute up to as high as 7,500. It is 
recommended that for most grinding operations surface speeds should 
not exceed 6,000 feet. As a wheel wears down the speed is increased 
to maintain the same surface speed, and great care must be exercised 
when a new wheel is provided to avoid over-speeding. 

102. Ladders, Order 11. (a) All movable ladders (except substan- 
tial stepladders) must be provided with either sharp points at the 
foot or wide, rough surface feet, or other effective means to prevent 
slipping. Ladders for use in oiling overhead shafting, where neces- 
sary to rest the same on the shafting, must be arranged to hook over 
the shafting. 

■103. Stairways. Order 12. All stairways must be equipped with 
handrails, the top of which shall be thirty (30) inches vertically from 
the nose of the tread, as follows : 

(a) Where the stairway is not built next to a wall or partition, rails 
must be placed on both sides. 

(b) If stairway is closed on both sides, at least one handrail must 
be provided. 

(c) If width is greater than four (4) feet, rails- must be provided on- 
each side. 

(d) If width is eight feet or greater, rails must be provided on each 
side and in center of stairway, except in cases where in the judgment 
of the Industrial Accident Commission a center railing would be 
impracticable. 

(e) All stairways must be properly lighted either by natural or arti- 
ficial light. 

Note. — Stairways sliould not be built at a sharper angle tlian fifty (50) degrees. 
For sharper angles, ladders should be used instead. 



\ 



LIBRARY OF CONGRESS 



013 971 701 6 



ND e TH 
•4 THE 

School 

CALIF. 



